What's the difference between wandering poems and homesick poems? Be specific.

There is no difference. Usually, we classify these two words into one category, which are collectively called homesick poems. People who don't know what this detention means will know the feelings expressed in this poem when they see homesickness.

Some poets have no fixed place for a long time, or live far away from home, or wander abroad, or seek careers, or be relegated on the way to their posts, or visit relatives and friends. The so-called "detention" means living in other places for a long time because of the above reasons. This kind of poetry expresses endless homesickness, endless thoughts and frustrations for relatives. To read this kind of poems, we should have a general understanding of the poet's history and experience, so as to understand the poet's feelings.