--Linux in a broad sense: Linux distribution --Distribution form organized so that Linux can be used --Linux in a narrow sense: Linux kernel --Hardware and software neutral
Linux itself is just the kernel of the OS. To actually use it, you need to add the following functional layer
--Device driver --Shell --Daemon --Command
--Providing a basic environment for the application to work --Where to store the data in memory --How much CPU resources should be allocated to which application? ――There are two main roles --Responding to requests from applications --Telling the application the response from the hardware
--What is a process? --A management unit that allocates resources such as memory and CPU --Data used by the running program will be used after being written to memory. --Data as a result of calculation --Value entered on the command line --Data acquired by communication --The CPU is performing operations on data in a certain memory according to the program. --The program runs as a process on the OS on the allocated resources. --The process basically terminates when it fulfills its role, freeing up resources such as memory. --Zombie process --A process that has finished its role but does not release memory. --The user will issue a kill command to forcibly terminate the process.