White tie is a fancy way of dressing up for really important events like balls or fancy dinners. Imagine you're dressing up like a prince or princess. It's kinda like a costume, but for grown-ups.
For guys, think of it like wearing a tuxedo, but fancier. Instead of a regular black jacket, you'll wear a special one that's longer with tails that go down the back. You'll also wear special pants that have a stripe going down them and a special shirt that has a stiff front and a bow tie that's big and poofy.
For girls, it's all about the dress. You'll want to wear a long gown that goes all the way to the floor. It can be any color, but traditionally it's a light color like white, ivory, or pastel. You'll also want to wear special jewelry and maybe even gloves to complete the look.
Overall, white tie is like a really fancy way of getting dressed up, and it's usually reserved for the most special of occasions.