No toes, no shoes, no soles here folks. In literary circles, this term refers to the most basic unit of a poem's meter.
A foot is a combination of stressed and unstressed syllables. There are all kinds of feet in poetry, and they all sound different, so we'll give you a handy list. If you want to be the nerdiest nerd in the nerd herd, you should memorize it:
A combination of feet makes up a line of meter. So, for example, the most common meter in English poetry is iambic pentameter, which contains five (that's where that "pent-" comes from) iambs, all in a row.
Finding your feet can be as tricky as learning the Viennese Waltz, but that's the main task of scansion, a fancy term for analyzing a poem's meter. Just remember the list above, and read aloud, read read aloud.