"Gang" means the number of separate physical switches sharing the
plate.

"Ways" is a separate concept, describing the number of distinct,
active current paths provided.

And just to add, as well as "ways" and "gangs", you also get "poles".

An additional pole is an additional switch that is affected by the same
switch mechanism. It is different from a gang, which is an additional switch
with an independent mechanism.

Light switches are usually single pole, so there is only one switch, which
should disconnect the live only. Switches for power circuits are now usually
double pole. This means that the one switch can turn off the live supply AND
the neutral.

Christian.