What is the difference between TTcpClient/TTcpServer and TClientSocket/TServerSocket?

Question

Could someone please explain their differences? Are they same and work the same way? Which one is better than the other components?

Answer 1

They are NOT the same, and they DO NOT work the same way. They take very different approaches to socket API interactions, event handling, error handling, etc.

TClientSocket and TServerSocket are the original VCL-based (Windows-specific) socket components. They were deprecated in Delphi 7 and are no longer installed by default, but are still available for manual install if you want to use them.

TTcpClient and TTcpServer were originally introduced in Delphi 6 as a cross-platform socket solution for Kylix (which is a dead product). They were removed from Delphi in XE6, downgraded to demo status, not even official components anymore.

In my opinion, TTcpClient and TTcpServer are horrible components, you should stay away from them. They use a very minimalistic "least common demoninator" approach to cross-platform programming, catering only to a few basic functions that multiple platforms support, not leveraging any platform-specific features or even higher-level functions. They have a very basic interface that is badly designed. They are very difficult to work with, have bad error handling, and are not very flexible to use.

If you need to write new socket code, TClientSocket and TServerSocket work great if you are only interested in supporting Windows, but if you need to support cross-platform then you should use a third-party socket library, such as Indy (TIdTCPClient/TIdTCPServer), ICS (TWSocket/TWSocketServer), Synapse (TTCPBlockSocket), etc.