In a similar way to みたい
is used when making observations about something in Japanese. This 助動詞（じょどうし） (auxiliary verb) is used to express three primary things.
たとえ - Using (A) as an example to highlight the way that (B) looks/is acting.
推定（すいてい） - Using (A) as a reason for an assumption made about (B).
例示（れいじ） - Presenting (A) as an example of what (B) is.
is usually based on direct information/experience, and shows that the speaker has high confidence in what they are saying. It may also frequently appear in its kanji form, 様（よう）だ.
can be used with any verb, い-Adjective
, or noun. However, it requires な before it when used with な-Adjectives
, or の
when used with nouns.
It seems like a big building will be made here.
It seems like the pool over there is deep.
He is telling everyone that he is confident about the test tomorrow, but it seems like he is actually worried.
Yoda appears to be an alien.
are often used in similar situations, そうだ
shows that the speaker has a lot less confidence in their statement than ようだ
. Because of this, ようだ
is a much better choice when stating things that are obvious/observable by anyone.
ようだ is considerably more formal than みたい, and is therefore less common in casual conversation.