Compared to roller skates, rollerblades have taller, more supportive boots. The wheels on rollerblades stay in line (one behind the other) while the wheels on roller skates have a 2 x 2 arrangement, 2 wheels at the front, and 2 wheels at the rear.
A rollerskate is basically a boot mounted on two skateboard-like trucks that support a set of four wheels. These skates look like typical shoes or everyday lifestyle boots