In plain words
Startup is the full path from power-on to a working session.
Why learners confuse it
Boot is one stage inside startup, so people often blur them together. Keeping them separate makes diagnosis calmer.
Startup is the larger process of getting the system from power-on to a usable desktop or shell.
A lot of people call every early problem a boot issue. Some failures happen later in startup instead.
Startup includes multiple stages such as hardware checks, boot, operating-system loading, services, login, and user environment readiness.
Startup is the full getting-ready process that makes the computer usable.
Startup is the full path from power-on to a working session.
Boot is one stage inside startup, so people often blur them together. Keeping them separate makes diagnosis calmer.
Study the larger concept after the word itself becomes clear.