The Lesson
A term is a collection of numbers, letters and brackets all multiplied together. Terms are separated by + or  signs in an algebraic expression.Dictionary Definition
The Oxford English Dictionary defines a term as "in an algebraic expression: each of the components that are connected by elementary signs of arithmetic, esp. those of addition and subtraction."Real Examples of Terms in Algebra
It is easier to understand terms with examples.
A term can be a number:

A term can be a letter:
The letter can be a variable (that can take any value) or it can be a constant (that only has one value). 
A term can have a number and a letter together:
The number is multiplying the letter. 2 is the coefficient of x. 
A term can have two or more letters next to each other:
In this case, the letters are mutiplying each other. 
A term can have letters which have an exponent.
An exponent tells you how many times that letter is multiplied with itself 
A term can contain brackets next to other numbers and letters:
The parentheses muliply the rest of the term.
Read more about how to mulitply letters
Terms in an Expression in Algebra
Terms are separated by + and  signs in an expression.Expressions are built from terms that are added or subtracted together.