What is the main difference between matlab and simlink

I am trying to understand when someone would use matlab over simulink or use simulink instead of matlab.

Answer 1

[Stephen23]

MATLAB (MATrix LABoratory) is a programming language and computational environment.

What it’s used for:

• Numerical computing
• Data analysis & visualization
• Algorithm development
• Signal & image processing
• Machine learning

Simulink is a graphical simulation tool built on top of MATLAB.

What it’s used for:

• Modeling dynamic systems
• Simulating real-world processes
• Control systems design
• Embedded systems and hardware simulation

[Evan]

but PID for example is an algorithm and is done in simulink. So if I was tring to compute the capacitnce a cylindrical cell has based off the size of the cell that would be simulink or matlab?

[Walter Roberson]

You can create PID controller systems in either MATLAB https://www.mathworks.com/help/control/ref/pid.html or Simulink

See also https://www.mathworks.com/help/control/ref/tunepidcontroller.html