Constant: A value that doesn't change. Instead, it's a fixed value.
Variable: A symbol (usually a letter) standing in for an unknown numerical value in an equation.
Term: Either a single number or variable, or numbers and variables multiplied together. (Terms are separated by + or − signs, or sometimes by divide.)
Like Terms: Terms whose variables (and their exponents such as the 2 in x2) are the same. In other words, terms that are "like" each other.
Coefficient: A number used to multiply a variable.
