It connects stuff.

Haversian system is part of compact bone, which itself is a connective tissue.

Connective tissues have an extracellular matrix that gives them their characteristic properties. Blood is a liquid connective tissue that has a fluid matrix.

Technically they are the same.

Fibrous connective tissue is basically any kind of connective tissue different than adipose and areolar. The fibrous connective tissue has more fibroblast and collagen fiber (a characteristic of dense connective tissue) but no much of elastic fibers (which is the histological difference with cartilage). Of course, we have to exclude blood, lymph and bones from the fibrous tissues because they are specialized connective tissue and have totally different characteristics than dense and loose connective tissue.

The extracellular matrix is a characteristic of connective tissue.