A font style command that produces bold upright text commonly used for algebraic structures and abstract categories.
Examples
Vector notation in linear algebra
\mathbf{v} = \mathbf{a} + \mathbf{b}
Matrix equation with bold variables
\mathbf{A}\mathbf{x} = \mathbf{b}
Force vectors in physics
\mathbf{F} = m\mathbf{a}