Solar coronal loops are still problematic to explain. Two main problems remain: The uniform emission along the high arching loops and their almost constant diameter. It has lately become clear that solar coronal loops are not simple structures, and since they have been called 'the building blocks of the solar corona', it is important that we understand these two basic properties of coronal loops. A short overview of previous observations and modeling of coronal loops in general will be given, as well as the latest contribution from this institute to answering the questions about solar coronal loops.