A polite expression (the polite form of 'sou da') used to agree or indicate that something appears or seems to be so ('that is so' / 'it looks that way').
それは本当ですね。そうです。
That's true. That's right.
見たところ、彼女は疲れているようですか？ — ええ、そうです。
Does she look tired? — Yes, she does.
説明のとおり、今回の計画は実現可能だそうです。
According to the explanation, it seems that this plan is feasible.
A polite hearsay expression. Placed after the plain form of a verb or adjective to mean 'I hear that...' or 'it is said that...'.
明日は雨が降るそうです。
I hear it will rain tomorrow.
彼は来ないそうです。
I heard he won't come.
あの店はもう閉店したそうです。
I heard that shop has already closed.