Process: When a program is running on the server, the collection of computing resources it occupies (the sum of occupied CPU, memory, disk, etc.) is called a process.
Processes do not interfere with each other - communication between processes is difficult.
Thread: The smallest unit of program execution, the smallest execution flow of response operations, and
the thread also contains its own computing resources. Threads belong to processes, and a process can have multiple threads .
Multi-threading: In a process, there are multiple threads executing concurrently .
