UTC stands for Coordinated Universal Time. It is the primary time standard by which the world regulates clocks and time.

While UTC and GMT are often used interchangeably, GMT (Greenwich Mean Time) is a time zone based on the mean solar time at the Prime Meridian (0° longitude) in Greenwich, London. UTC, on the other hand, is more precise and is based on atomic time, making it more accurate than GMT.

UTC is important because it serves as a global time standard, allowing people around the world to coordinate activities, schedules, and communications across different time zones.

UTC does not observe daylight saving time. It remains constant throughout the year, unaffected by DST changes. However, some regions may adjust their local time relative to UTC when they observe DST.

The UK uses UTC time when observing DST and British Summer Time (UTC +1) otherwise.