You connect to other p2p users (ie: peer to peer.) And we share files b/w ourselves. Be it music, videos, photos, poetry, etc. It will be wise to read some optimising tips & search & dwnld hints:
Tip 1 - 1st post only (click on link) & also Tip 2 (click on link) & also Tip 3 (click on link)

But just to make sure you're not having any connection problems due to Limewire (LW) being blocked due to firewalls, etc. Do the following test & make sure your result is True. If it is False post back here to this thread: Firewall check (click on link) If your result is false then we'll need to discuss how to allow LW thru your firewall/router, etc. Good luck. Sharing files helps.
Sharing files also helps you to connect to other peers & thus connect easier & find more results when searching. How to Share files (click on link) & mac images found further down the page.