The particle は is used to identify the topic of the sentence, then provide information about that topic.緑茶は 日本の お茶です。
Verb in て-form + いますN5
Expresses the current state or an ongoing action, or a state that continues as a result of a certain action.カテキンが 入っていて、体に いいです。
Noun + に + はN5
The structure には emphasizes the place, object, or scope to which the action or state applies, and is often used for emphasis in a sentence.緑茶には カフェインも 入っています。