Speed is a scalar quantity, where as vector is a vector quantity.
For example let us take a particle which moves in positive direction with speed 16 feet per sec, its velocity also 16 ft/sec since the particle is moving in positive direction (positive x-axis).
If the particle moves in negative direction with same speed 16 feet per sec,
its velocity is -16 feet per sec.
Hence the 2 velocities for which speed is 16 feet per sec are +16 feet per sec and -16 feet per sec.
