They form an expression. Terms are separated by operators, and joined by grouping symbols. Expressions are made up of terms and operators (since, you know, operators separate terms).

Terms, expressions, symbols, all those are terms about syntax. Not semantics. Do you start to notice something?

Why would I want to when you ignore Maths textbooks and proofs?

To learn. I challenge you again to explain the difference between syntax and semantics. Last chance.