What End Do I Use for What Purpose?
If you are in a hurry, the short answer to that questions is: Females always hold the power. A Male end should plug or "mate" with a Female end to receive electricity to power a device. If you want to see a few more words from someone who cares, keep reading for the long answer:
When you think about "jacks" or "plugs" or "connectors" or "sockets," many different images may come to mind. Some may think about the AC wall outlet in your home. Others may think about that "jack" you "plug" in the back of your computer to do XYZ. However, most of you are here to learn about the connectors that are sold on this site. In anatomy class, we learned that males have a physical protrusion and females have a physical inversion. The same goes for most connectors that carry electrical power or signals. Sometimes, there will be an obvious male and female in the connector set such as the US AC extension cord pictured here.
Sometimes the gender of the plug will not be as obvious, such as this xConnect connector. Since the male side has a shell around it to protect the prongs, the female end is inserted into the male end.
Then there are connectors that are regarded as hermaphroditic, other names would be sexless, gender-less, or combinations connectors. These connectors have both a male and female sex part that is interchangeable allowing it to connect with one another without regards for which side is which.
The sexless connectors are different from bisexual or mixed-gender style connectors that have both male and female anatomy, but either side is different so that it may receive its mate.