Any algebraic expression with two terms is called a binomial expression.
2x+3y, here we have two terms, they are \(2x\) and \(3y\). Thus this expression is called as binomial expression
3x2y7xy is a binomial
3x2y+(7yx)=3x2y7yx is also a binomial
Like we have already seen in addition and subtraction of algebraic expressions, when adding or subtracting only the like terms are added or subtracted.
Let us look at an example and discuss the terms of a binomial and a degree of a term.
It is very important to keep in mind that a binomial expression has only two terms. This is the reason why it is called a binomial (prefix 'bi' stands for 'two').  
2x+3y here the terms of the binomial are 2x and 3y                                             
Degree in an algebraic expression is the sum of the exponents of the variables in the expression.
7xy23y2z  here
terms of the binomial
degrees of the terms
\(2+ 1 = 3\)
\(2 + 1 = 3\)