Hey there!
A binomial is a polynomial that contains two terms. Terms are separated from one another by mathematical symbols, such as +, –, and ×. A term can be a variable, a variable with a coefficient, a constant, or really any combination of coefficient, variable, and exponent that you can think of. For example...
(3x² – xy)
(x + 3)
(5x – 6y)
...are all binomials.
Hope this helped you out! :-)