How does garbage collection work at a high level?
PICTURE THIS: HOW TO EXPLAIN IT
Simple meaning
The GC tracks reachability from roots and reclaims objects with no references.
WHY — GC instead of guessing?
Why interviewers care about GC:
question about GC.
trade-offs, and what you would actually do on a .NET project - not buzzwords.
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:
- 1The GC tracks reachability
from roots and reclaims objects with no references.
- 2It uses generations so
short-lived objects are cheap to collect.
- 3I never call Collect
in production code unless I am diagnosing a leak.
- 4Give an example
One tiny concrete case you can say aloud.
- 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
The GC tracks reachability from roots and reclaims objects with no references. It uses generations so short-lived objects are cheap to collect.