fs :[0x01] References

[buck12]

So I have seen this many times and even on Ollydbg discussions when viewing code but could never figure it out.
fs :[0x01] PEB Process Environment Block.

I tried searching for it on the dump window but could never find it Control +G.

Can someone explain to me what this is trying to say and how it applies to Ollydbg for example fs :[0x01]?

Thanks

[dedndave]

google Thread Environment Block (TEB) or Thread Information Block (TIB)