Tell me. to test TCP and UDP ports

netcat can do everything that you need.

> Tell me. to test TCP and UDP ports.
\r
nmap, telnet
\r
> With the possibility of sending data manually to the port (for example, for testing
> HTTP is sometimes useful to drive the request headers).
\r
curl, wget, telnet

nmap crossplatformed and that does it. By itself, it is a console, but there are GUI. For example, under Windows you can use Zenmap. If I remember correctly — it is included in the installation package.

You can still nc.
To send data:
echo "GET /" | nc localhost 80
Listen to:
nc-l localhost 8080