The projection of a vector on another vector is:

The projection of a vector $\vec{a}$ on $\vec{b}$ is given by the formula:
$${\text{Proj}}_{\vec{b}}\vec{a}=\frac{\vec{a}\cdot \vec{b}}{|\vec{b}|}$$
Since the dot product $\vec{a}\cdot \vec{b}$ is a scalar and the magnitude $|\vec{b}|$ is a scalar, the resulting projection (often called the scalar projection or component) is a scalar quantity. Note: While "vector projection" results in a vector, in general mathematical contexts of this level, "projection of a vector on another" refers to the scalar magnitude of that projection.