The Ports collection / FreeBSD CDs

[Arindam]

I am a Linux user and have been recently trying to shift to FreeBSD. I
got hold of a couple of FreeBSD CD ISOs (version 6.1) - their names
being 6.1-RELEASE-i386-discX.iso, X being 1 and 2.

I did my installation with the Disc1 alone. I did not need Disc2. What
is the purpose of Disc2 and what can I do with it.

I chose not to install the ports collection because as of now, I do
not have access to Internet in my home-network and it would take a
little while before I can set it up for browsing. Does Disc2 contain
some of the ports collection?

Finally, what is the ports collection?

Cheers!