Three types of muscle tissue

Skeletal muscle tissue- The structure is that it has dark and light lines going across it. The function is to have movement in various bones.

Cardiac muscle tissue- The structure is similar to a Y shape and has a single nucleus. Function is to pump blood through the heart.

Smooth muscle tissue- Responsible for contractility of hollow organs such as blood vessels. Lack of visible cross stations and fibers are much smaller than skeletal fibers.

Smooth muscle doesn't visually have fibers.
Skeletal muscle visually has fibers.
Cardiac muscle is a mix between both.