Expression
Domain: Programming Fundamentals
🎯 Motivation
An expression is any piece of code that produces a value - math, function calls, comparisons.
📋 Concrete Example
3 + 4 is an expression (value 7). x > 5 is an expression (value True). len('hello') is an expression (value 5).
🔗 Analogy
A math problem on a test - when you solve it, you get an answer (a value). The problem itself is the expression.