2y - z + z^2 is an algebraic expression. It represents a mathematical operation that includes three different terms: 2y, -z and z^2. It can be simplified depending on the context and the values of y and z.
In the given expression, 2y is the coefficient of y, which is multiplied by y. -z is subtracted from 2y and z^2 is added to the result.
In order to simplify this equation, you could combine like terms, which means combining the same variable or powers of the same variable with each other.
This expression does not have any like terms, so it can't be simplified anymore.
It can be evaluated by replacing y and z with specific values and then performing the mathematical operations in the given order.