What is what type of tissue is blood?

Blood is a connective tissue. While this might seem counterintuitive because it's a fluid, it fits the definition of connective tissue because it connects different parts of the body and contains a matrix (the plasma) embedding various cells. Unlike other connective tissues like bone or cartilage which have a solid extracellular matrix, blood's matrix is liquid. This liquid matrix allows for the transport of cells, nutrients, and waste products throughout the body.