What is the difference between type and interface?
PICTURE THIS: GIT FLOW
Simple meaning
Both describe object shapes
WHY — TypeScript instead of guessing?
Why interviewers care about TypeScript:
contrast on TypeScript, not two memorised paragraphs.
the developer, then one case where picking wrong hurts.
Name the idea, why it exists, then one short example.
End with when you use it and one common pitfall.
STEPS — What happens step by step?
Before you speak the answer, walk the interviewer through these steps:
- 1Define it
Both describe object shapes
- 2interfaces can merge across
files and feel natural for public object contracts.
- 3Type aliases handle unions,
tuples, and mapped types more cleanly.
- 4In practice I use
interface for component props and type for unions.
- 5Common mistake
What juniors usually get wrong.
- 6Close
When you pick this over the alternative.
EXAMPLE — See it in action
Here's a short line you can speak, broken into clear beats:
Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.
Key takeaway
Both describe object shapes interfaces can merge across files and feel natural for public object contracts.