WhatsApp is a popular messaging app that allows users to send messages, photos, videos and files to individuals or groups. It operates through internet data plans on smartphones and is particularly useful for communicating internationally due to the low cost compared to SMS or calling. WhatsApp was created in 2009 by Brian Acton and Jan Koum, former employees of Yahoo. It was acquired by Facebook in 2014 but continues to operate as a separate app with over 1 billion users worldwide.
Key Features of WhatsApp
Some of the key features that make WhatsApp popular include:
- Free messaging – WhatsApp uses the internet to send messages so there are no SMS costs. The only cost is the internet data plan.
- Group chat – You can create groups with up to 256 participants to communicate efficiently with teams, families or friends.
- Media sharing – You can send photos, videos, GIFs, voice messages and more to further the conversation.
- Document sharing – Share PDFs, spreadsheets, slideshows and other documents up to 100MB in size.
- Voice and video calls – Make free VoIP calls to individuals or groups when you want to chat instead of text.
- End-to-end encryption – Messages are secured with end-to-end encryption so only the sender and recipient can read them.
- Offline messaging – Even without an internet connection you can compose and queue messages to send later.
- Status updates – Share text, photos, videos in your status that disappear after 24 hours.
- Platform flexibility – WhatsApp works on iOS, Android, Windows Phone, Blackberry and Symbian smartphones.
These features have made WhatsApp a versatile and popular communication tool for both business and personal messaging globally.
How Does WhatsApp Work?
WhatsApp operates through phone numbers as unique IDs for users rather than separate usernames. To use WhatsApp you first need to download the app and set up an account. Here is an overview of how WhatsApp works:
Downloading and Verifying
To get started you first download the WhatsApp app from the App Store or Google Play Store. Once it’s installed open up the app and agree to the Terms of Service. You’ll then be prompted to enter your phone number which will be verified automatically through an SMS code sent to your phone. This verification process links your account and number.
Adding Contacts
With your account set up you can start adding contacts. This is done through your phone’s address book which WhatsApp will upload and match to other WhatsApp users. You can also search for specific numbers or names and send invite messages. Groups can also be created by adding multiple contacts.
Messaging
Once contacts are added you can start messaging them through text, voice notes, media and documents. Messages will indicate if they are successfully delivered and read. You can see when contacts are typing and also send your location through the app.
Settings
There are numerous settings in WhatsApp to control notifications, privacy, data usage and more. This includes options like only being available to contacts, turning off read receipts and limiting message downloads. You can also set when you’re available through statuses.
Web and Desktop Apps
While WhatsApp started as a smartphone app, there are also web browser and desktop apps available. These sync to your phone so you can send messages through your computer as well. This makes it easy to message from phones, tablets, laptops or PCs.
The Technology Behind WhatsApp
WhatsApp employs a variety of technologies to enable its messaging capabilities and unique features. Here are some of the main technical elements behind the app:
Erlang
WhatsApp was built using Erlang which is a programming language useful for concurrency, distribution and fault tolerance when creating real-time messaging apps at scale. It utilizes the principles of functional programming to enable WhatsApp’s performance.
FreeBSD
The WhatsApp server infrastructure runs on FreeBSD which is an open source operating system. The reliability and security of FreeBSD helps WhatsApp efficiently operate across its global server network.
HTTPS Encryption
WhatsApp relies on HTTPS encryption for secure transmission of data. This ensures messages, files and information sent through WhatsApp has transport layer security as it travels between the app and WhatsApp’s servers.
Whisper Systems
To enable end-to-end encryption, WhatsApp uses the encryption protocols developed by Open Whisper Systems. This allows only the communicating users to read messages and prevents access by anyone else, including WhatsApp.
XMPP and MQTT
For instant messaging capabilities, WhatsApp adopted XMPP (Extensible Messaging and Presence Protocol). It also uses MQTT for push notifications to alert users of new messages and events. Together they enable real-time communication.
QR Codes
WhatsApp uses QR codes to seamlessly sync desktop apps with a user’s mobile account. By scanning the code displayed on your mobile device, WhatsApp can transmit login credentials and encryption keys.
Group Messaging
A popular WhatsApp feature is the ability to use it for group chats. Here’s an overview of how group messaging works on WhatsApp:
Creating a Group
Groups are created by opening the Chats tab and selecting “New Group”. You’re able to add existing contacts as well as numbers not already in your address book. Give the group a name and optional icon.
Group Admins
The creator of a group is the default admin but they can add other contacts as admins. Admins can make changes to the group like adding or removing participants. They have control over the group.
Messaging
Once a group is created, members can freely message each other and see the conversation history. All messages are end-to-end encrypted. Users can only see messages from when they joined.
Up to 256 Participants
WhatsApp supports up to 256 participants in a single group. With this many people messaging, groups are ideal for teams, events, families, friends or communities.
Management
In addition to adding admins, there are settings to control notifications, visibility of members, invitation links and the ability to rename groups or remove contacts. This gives control over groups.
Mute or Leave
To manage notifications, any user can mute a group for a set duration or even leave it if desired. Leaving removes access to future messages from the group chat.
Voice and Video Calls
Voice and video calling are popular ways to communicate on WhatsApp with individuals or groups:
High Quality
Thanks to data compression algorithms, WhatsApp provides high quality VoIP calls through minimal data usage. This makes calls a convenient option.
Encrypted
As with messaging, WhatsApp employs end-to-end encryption for voice and video calls to keep them secure and private. No third party can access calls.
HD Video
Video calls are made available in HD providing high resolution video up to 720p for smooth video chat. This relies on your smartphone camera and internet speeds.
Data or WiFi
Calls can be made over your phone’s mobile data or any WiFi network. This gives you the flexibility to call from anywhere with internet access.
Group Calls
Up to 8 participants can join a group call. This makes it great for chatting with teams, families or groups of friends conveniently on a multi-way call.
Low Cost
Because calls route through the internet using data plans, there are no associated charges from your carrier. Just the costs of your data use.
Sending Media and Documents
Sharing photos, videos, GIFs, documents and other multimedia files is a big part of the WhatsApp experience:
Photos and Videos
High resolution photos and videos can be shared to individual or group conversations. These auto-compress when needed to allow quick sending even on slow networks.
GIFs
The GIF library in WhatsApp makes it easy to find and share funny animated GIFs in your conversations for extra emotional expression.
Voice Messages
In lieu of typing out long messages, you can quickly send short voice messages by holding down the mic icon and speaking. These can convey emotion and tone.
Documents
Files and documents like PDFs, spreadsheets, slideshows and more can be sent for business or personal purposes. WhatsApp compresses these for sharing.
Location
To help others find you or know where you are, locations can be shared through WhatsApp either using live location or general map pins.
Message Retention
Multimedia can take up storage space so WhatsApp provides controls over auto-download settings and duration of media retention before it’s deleted.
Security and Privacy
As user data and communications are sensitive, security and privacy are vital parts of WhatsApp’s operation:
User Account Security
Accounts are secured through automatic encryption, 2-step verification for added security and account lock after periods of inactivity to limit unauthorized access.
End-to-End Encryption
Messages, calls and shared media are automatically encrypted end-to-end so only the sender and recipient can view them. Not even WhatsApp has access.
Media Encryption
In addition to transport encryption, media like photos and videos have additional encryption applied to their content for an added layer of protection.
Backups
Chat history can be backed up to Google Drive or iCloud for safety but these backups are also encrypted for privacy. Backups can be password protected too.
Blocking Contacts
To prevent unwanted messaging, users can block specific contacts which will remove ability for them to message or call until unblocked. Useful for privacy.
Reporting
If any abusive behavior occurs, such as spam or scams, users can report other users or groups which may result in blocking and removal. This keeps WhatsApp safe.
WhatsApp Status Updates
Alongside messaging, an optional WhatsApp feature is the ability to share status updates:
Temporary Sharing
Statuses allow sharing text, photos and videos that disappear after 24 hours. Others can view but statuses are not permanent.
Control Viewers
You can configure statuses to be visible to everyone, just your contacts or exclude specific contacts. This controls who can view status content.
View Other Statuses
By tapping on the Status tab you can scroll through status updates from your contacts in reverse chronological order to see what they’ve recently shared.
Limited Access
For privacy, contacts can only view your status content once, unless you configure it to always allow multiple views for specific contacts.
Reply to Statuses
Directly replying to statuses allows you to start a private conversation based on the content someone shared in their temporary status update.
Status Notifications
You can enable notifications when chosen contacts share status updates so you’re alerted to new statuses from specific people.
WhatsApp Business
There is a specialized WhatsApp Business app designed for small businesses:
Business Profiles
Profiles are customizable with business descriptions, email addresses, store addresses, and other details. This helps identify businesses.
Messaging Tools
Specialized tools like quick replies, greeting messages, and away messages help businesses communicate efficiently through the app.
Analytics
Stats like how many messages sent, read receipts and client interaction help businesses understand engagement and impact.
Automated Messaging
Bulk messaging and notifications help businesses reach customers without manual effort. Useful for appointment reminders, alerts and campaigns.
Free to Download
WhatsApp Business is free to download making it easy for small businesses to get started with the app and utilize its communication tools.
Supports iOS and Android
The business app can be used on both iOS and Android devices so businesses can utilize it across multiple smartphones.
Conclusion
WhatsApp has revolutionized messaging and remains the most popular platform worldwide. Its features like free messaging, group chat, voice and video calling, media sharing and encryption have made it indispensable for both social and business communication. The app runs reliably through a global infrastructure yet is simple to use across smartphones. While competitors have emerged, WhatsApp’s continued innovation around privacy and multimedia ensures its popularity extends into the future. With over a billion users it has become part of daily life for much of the world.