Seeding and Portforwarding help.

im pretty noob when it comes to torrents, all i know is download and seed. So my question is, how come when i seed i dont see anything happening? Whats the point of seeding? Is it just to give upload speed away to other downloaders? im not really good with the whole point of seeding lol.

Also i have tried portfrowarding my utorrent. I made a static ip and portforwarded the port of my utorrent. its a success. They say portforwarding is supposed to get your dl speed higher but so far it been the same. anyone know why?

Any help would be appreciated. Thanks!