Lexical Analysis takes the raw code and splits it apart into these things called tokens by a thing called a tokenizer (or lexer).
Tokens are an array of tiny little objects that describe an isolated piece of the syntax. They could be numbers, labels, punctuation, operators, whatever.
Here’s an example of lisp:
(add 2 (subtract 4 2))
which when parsed in to tokens would look like this:
[
{ type: 'paren', value: '(' },
{ type: 'name', value: 'add' },
{ type: 'number', value: '2' },
{ type: 'paren', value: '(' },
{ type: 'name', value: 'subtract' },
{ type: 'number', value: '4' },
{ type: 'number', value: '2' },
{ type: 'paren', value: ')' },
{ type: 'paren', value: ')' }
]