how does expanders and noise gates work

[so-fye]

ive seen lots of expanders but i dont't know what they do or how they work, same wit a noise gate and waves seem more difficult. i see that they have some nobs like a compessor and limiters.

[whomper]

expanders are the opposite of compressors
you can get more dynamic range at teh cost of slightly less accurate signal

gates give silence unless the signal is higher than the set level
that blocks noise on rests with no signal or very quiet passages
gives an apparent improvement in s/n

[so-fye]

so these two things will have every thing sound more clear with some of the noise beind cut. also i heard that a expander can boost your drums or instruments to.

[whomper]

amplifiers boost

not sure anything will be clearer
but on soft passages there will be less noise
and less apparent noise overall

expanders expand - everything -
never use them but i would think expand both down and up
so you might get some apparent gain in loudness