The difference between Epithelial Tissue and Connective Tissue is that the former is made up of cells and negligible amount of intercellular matrix whereas the later is made up of cells and a large amount of intercellular matrix.
Skeletal tissues are composed of solid matrix and cells. It includes notchordal tissues. Cartilages and bones. It forms endoskeletal elements in chordates. It protects and supports the soft part of the body.
Connective tissue is made up of a large amount of intercellular matrix of fibres or both and living cells. On the basis of nature of matrix connective tissue is of 3 types. They are connective tissue proper, skeletal tissue and fluid connective tissue.