What's the difference between latching and non latching foot switches?

Neil

I probably sound dim but I was thinking of getting a channel changing foot switch for my old Marshall Valvestate and I am confronted with latching and non latching pedals.

Can somebody enlighten me on the difference please and what I need? 

Gagaryn

Latching has two positions - on a and off. Non latching is momentary - it' only engaged when its pressed and returns to open when you step off.

ICBM

For a Valvestate you need latching.

hugbot

non-latching is for tap tempo and keyboard sustain. latching is for amps (usually)

Neil

Thanks Gents, just the info I needed.