System initialization is the process that prepares a computer or device for operation. It involves loading the necessary software and configuring hardware settings to ensure everything functions correctly. This step is crucial for the system to recognize its components and establish communication between them. During system initialization, the BIOS or UEFI firmware performs a power-on self-test (POST) to check for hardware issues. Once the tests are complete, the operating system is loaded from the hard drive or SSD, allowing users to interact with the system and run applications.