== Ravi Dwivedi's personal website ==


(Last Updated: 9-September-2021)

Here are the definitions of the terms I use. If a nontechnical regular computer user fails to understand these terms, then I have failed.



A backdoor means someone can remotely access your system, like the software developer itself or any third-party bypassing normal authentication or encryption in a computer. For example, a backdoor was found in Microsoft Windows through which any change whatsoever can be imposed on the users.


Pieces of object code distributed without source, usually firmware to run some device.

Centralized Services

A service in which every user is on the same server or network of servers controlled by the same organization. Example: Signal, Twitter, Google Meet, Facebook, YouTube etc.

End-to-end Encryption

Only users exchanging message/information can read them.

Federated Services

Federation allows separate deployments of a communication service to communicate with each other - for instance a mail server run by Google federates with a mail server run by Microsoft when you send email from @gmail.com to @hotmail.com. Example: Matrix, XMPP, Mastodon, PeerTube.


Firmware is a software which provides a way for hardware to interact with the operating system. It runs on a secondary processor and not on the CPU. For example the WiFi chipset will run this code directly instead of the main CPU. For more details, please check my post on this topic.

Free Software

Free Software means that the users have the freedom to run, copy, distribute, study, change and improve the software. Example: GNU/Linux distros, Firefox browser, Jitsi Meet, Madtodon etc. Check out my Free Software list for more examples.


It means systems are able to freely exchange data with another by a known mechanism. For example, Telegram works on a different protocol than Matrix to send messages, but it is possible to join a Telegram channel using Matrix and vice-versa. This cross-protocol exchange of information is called interoperability in this example of chatting systems.


Software whose functioning mistreats the user is called malware.

Nonfree/Proprietary Software

Any software which is not a free software. A nonfree software does not respect users' freedom. Example: Microsoft Windows, Adobe Photoshop, WhatsApp etc.

Vendor Lock-in

Vendor lock-in means that the cost of switching to a product of another vendor is very high for the user. This makes user dependent on the product.

WhatsApp is an example of vendor lock-in. For WhatsApp users, switching to another chatting app comes at a high cost - losing all their contacts and convincing each of them to switch. Similarly, Signal and Telegram are also examples.