Module 1 · Introduction to Programming · Lesson 3 of 7
What makes a language
Whether it's English or Python, every language is built from the same four layers. Start with an alphabet of allowed symbols, combine those into a vocabulary of words, arrange the words using syntax rules, and the result carries meaning. Watch one Python statement come together layer by layer.
- Alphabetthe symbols you may use
- Lexissymbols grouped into words
- Syntaxwords arranged by the rules
- Semanticswhat it actually means
The alphabet is every character you're allowed to type. The lexis is the set of real words — keywords like print, names, numbers and symbols. Syntax is the grammar: the rules for how those words may be put together. And semantics is what a correctly formed statement actually does.
Break a rule in any layer and it stops working: an unknown character, a misspelled word, or words in the wrong order. Python will tell you — which is exactly what the next two lessons are about.