’S can mean:

- is (as in “it’s a nice day”)

- it is (a weird archaic poetic usage)

- God’s (also weird, eg ’Sblood)

- that’s e.g. ’sright

- has e.g. it’s got many meanings

- us e.g. let’s go on a walk

- his (also weird. Obsolete/dialect)

- as (eg so’s = so as)

- does when’s the band come on?

Naturally one can see several of these in one sentence, e.g. “let’s meet as soon’s Brian’s recovered from the fever he’s got.”