If you haven’t been to a gender reveal party before or are in the dark on what it is:
“A gender reveal party is a celebration during which parents, friends and family find out the sex of a baby. This has become possible with the increasing accuracy of various technologies of determining the baby's sex before birth. The first mention of such parties is from 2008 and is distinct from a baby shower, which is a gift-giving ceremony.
“Gender reveal parties are typically held near the middle of the pregnancy.”
Some very creative ideas are shared in the above video for the big reveal.