Of course!
UL is the Underwriters Laboratory. It defines safety standards for all sorts of consumer products, with a goal of providing consumers with a reliable way to know if a product is safe or not. It also can actually perform the tests to determine if the safety standards are met. If UL performs the tests, and the tests pass, a product is UL Listed.
https://en.m.wikipedia.org/wiki/UL_(safety_organization)
ETL is a British laboratory (aka Intertek) that does not define the standard, but will perform the tests to say whether or not the standards are met. Thus a product is said to be ETL Listed to conform to UL standards. Both UL and ETL are officially recognized as approved testing laboratories by the United States government.
https://en.m.wikipedia.org/wiki/Intertek
There are a few other officially approved laboratories.
https://en.m.wikipedia.org/wiki/Nationally_Recognized_Testing_Laboratory
Now, note that some products have a CE mark. This mark is a declaration by the MANUFACTURER, not a certification by a third party laboratory. As such, it is basically useless for determining whether or not a product is safe. Don’t be fooled by a CE mark!
https://en.m.wikipedia.org/wiki/CE_marking
Hope that helps!