# Linux & Systems
Linux and systems fundamentals explain what is actually happening below application code.
## Start Here
- [[Articles/Tracing System Calls at a High Level]]
- [[Articles/File Descriptors Part 1]]
- [[Articles/File Descriptors Part 2]]
## Field Notes
- [[Field Notes/File Descriptor]]
- [[Field Notes/Page Cache]]
## Learning Paths
- [[Learning Paths/Linux Internals for Backend Engineers]]