Polite form used to express that something seems to be the case or appears so (similar to 'seems' or 'it looks like').
今日は雨が降るみたいですから、傘を持って行ってください。
It looks like it will rain today, so please take an umbrella.
彼は疲れているみたいです。早く休ませたほうがいい。
He seems tired. You should let him rest soon.
この料理は辛いみたいですけど、大丈夫ですか？
This dish looks spicy; is that okay?
Polite form meaning 'as if' — used to liken a situation to something else (not stating a fact but making a comparison).
彼はまるでプロの選手みたいです。動きが違う。
He is like a professional player; his movements are different.
その景色は夢みたいですけど、本当に存在する場所です。
That landscape is like a dream, but it's a real place.
今日は忙しくて、まるで時間が足りないみたいです。
I'm so busy today it feels as if there isn't enough time.