UTC+10:00 means a time zone that is 10 hours ahead of Coordinated Universal Time or UTC. UTC is the standard time zone of the world. Timezones are often named by how many hours they are different from UTC time. For example, UTC -5 (United States east coast) is 5 hours behind UTC.
The UTC+10 time zone covers the following the east coast of Australia, Papua New Guinea, Micronesia, Guam, the Northern Mariana Islands and parts of Russia. The map shows the time zone. There are differences with Daylight saving time:
In Australia UTC+10 is called Australian Eastern Standard Time or AEST.