Summary: in this tutorial, you will learn about C variables that allow you to manipulate data in your program. A variable is a meaningful name of data storage location in computer memory. When using a variable, you refer to a memory address of computer.
Overheating of the CPU caused by a temperature problem is definitely a bad sign as it can destroy the processor and can cause instabilities in the hardware of the system. This can lead to it rebooting as well.
Overload means an excess current drawn, which will lead to tripping of the circuit breaker once the current exceeds 5 times the rated MCB current value within a tenth of a second (depending on the Type of MCB). When your electric load is faulty and there's a short circuit, a lot of current is drawn -> MCB trips. But an electric shock to a human being may not always draw an excessive current that is so high to trip the MCB and protect you. This is where RCCB comes in.