Please answer a question about the following article about Daylight saving time:

DST clock shifts sometimes complicate timekeeping and can disrupt travel, billing, record keeping, medical devices, heavy equipment, and sleep patterns. Computer software can often adjust clocks automatically, but policy changes by various jurisdictions of the dates and timings of DST may be confusing.

When the clock on your laptop adjusts to DST without you resetting the clock, what is controlling the change?
Computer software