Piracy: ꜱᴀɪʟ ᴛʜᴇ ʜɪɢʜ ꜱᴇᴀꜱ

For the end user: it's a program with everything included. You don't need to visit any website to find files to download. You can search directly what other people are sharing and download from it.

Now the client evolved since it first appeared but has maintained compability.

Initially you need to connect to a server that would list the files people connected to that server were sharing, then they added a DHT and now you don't need to use those servers. However people still use them mainly because the search is faster.

Please note that sharing is very easy. Just select a folder and you are sharing whatever is in that folder. This creates a lot content to share, but also the quality might not be good. For good quality it's better to have the files curated and for that i recommend to use a community that shares ed2k links (they are like magnet links) for the good and quality stuff (similar to use piratebay vs a private tracker - on pirate bay you might not get the best of whatever you want)