i think it depends on context but the expression "~것 같다" could be "guess" or "impression on something you've got".
for your guess,
비가 올것 같다
it's gonna be raining.
그가 파티에 올것 같다
i guess he's gonna come to the party.
i guess he might come to the party.
for impression on something,
what do you think about my idea on that?
well, it seems to be a good idea.
응 모든 문제가 해결된것 같아.
it seems as if all problems are solved.