# Expressions in Python

If you were to imagine Python to be a universe of its own, an expression would be the atom of this universe. An expression is the atomic unit of expression in Python.

### So, What is an Expression?

Expressions are representations of value in Python. Something like the expression `1+2` represents the value `3` in Python. Expressions are some combination of values, variables, operators, and function calls. Play around in the Python terminal with me, if you'd like to try a few expressions:

```python
>>> 1 + 2
3
>>> 1 - 2
-1
>>> 1/2
0.5
```

These are different from statements. Statements are a collections of expressions that together "do something". Expressions can be statements, but statements can't be expressions, if that makes any sense. Here's a few examples:

```python
>>> a = 3
>>> a
3
>>> a + 7
4

>>> def f(x): 
...    return x
>>> f(3)
3
```

Some of this syntax may not make sense to you — that's okay! Sometimes, a block of these statements do something unique and we wish them special names — like if statements, loops or functions. But the big idea to take away here is that **everything in Python is a collection of expressions and statements.**