When you open Snapchat, you are presented with a camera view. If you tap on the screen, various filters will appear. These filters can be used to change the way your photo or video looks. For example, there are filters that can make it look like you're in a different location, or make it look like it's night time. There are also filters that can add text to your photo or video. To use a filter, simply tap on it and then take your photo or video.