the other day; recently — referring to a recent time or a short while ago.
この間、田中さんに会ったよ。
I ran into Tanaka the other day.
この間買った本が面白かった。
The book I bought recently was interesting.
この間は忙しくて返信できませんでした。
I was busy recently and couldn't reply.
meanwhile; in the meantime — referring to the period during which something else is happening.
新しいパソコンが届くこの間、古いパソコンで仕事を続けます。
In the meantime, until the new computer arrives, I'll keep working on the old one.
引越しのこの間、友人に手伝ってもらった。
During the move, my friends helped me.
修理が終わるこの間、レンタカーを借りた。
While the repairs were being done, I rented a car.