Linux for Developers
/Intermediate
Linux Architecture
Definition
The layered structure of Linux: Hardware at the bottom, the Kernel above it, the Shell/System Libraries above that, and User Applications at the very top.
Explain Like I'm New
A multi-story building. Applications live in the penthouse. Hardware lives in the basement. Applications are never allowed to go to the basement directly; they must hand requests to the Kernel (the butler) to fetch things from the basement.
Real World Example
A Node.js app (User Layer) wants to read a file. It calls a standard C library function. The library executes a 'System Call'. The Kernel catches the System Call, spins up the physical hard drive (Hardware Layer), reads the file, and hands the data back up the chain.
Common Use Cases
- •Understanding system boundaries
- •Security isolation
Interview Questions
basic
- Do user applications interact directly with the physical CPU?
intermediate
- What is 'User Space' vs 'Kernel Space'?