The phrase "start computer" can be replaced with a number of synonyms that convey the same meaning. These include "boot up," "power on," "turn on," and "initialize." When starting a computer, it means you are initiating its operating system, which involves starting up all the programs and services required for it to function. The process of starting a computer can take anywhere from a few seconds to a few minutes, depending on the machine's speed and specifications. It's important to follow the correct process of starting your computer to avoid any glitches or malfunctioning in your system.