A simple way to under Tea house / Lodge is probably ‘a small hotel’. However this can sometimes be misleading, as they do not have high-end facilities like modern hotels in urban areas. The concept though is same as hotels in providing accommodations (rooms) and meals for guest staying in it.

So if one does a trek going from point A to B to C etc., and spending nights in these kind of lodges or teahouse is called a ‘Lodge Trek’ or ‘Tea House Trek’