What is the typical feature of the epithelia? How different is it from the connective tissue?

The typical feature of the epithelium is the absence or almost absence of space among cells. The epithelial cells are compactly positioned side-by-side with the help of specialized structures for cell adhesion such as desmosomes and interdigitations. This feature relates to the fact that these tissues are usually exposed to an exterior surround and so they require more resistance and impermeability against the entrance of strange material into the body.

The connective tissue presents opposite features because of its filling function. It has much interstitial material (the matrix) and relatively large space among cells.