system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What are the differences between different types of picture formats (jpg, png, gif, etc)? Are some better than others?
gpt
JPEG is a lossy-compression image format. What this means is that when the image is compressed, some of its details are discarded in order to make it take up less space. JPEG is designed to work on more natural pictures, mainly photographs, where close pixels tend to have similar colors, and compression artifacts are less noticeable.

GIF uses non-lossy compression. The main "feature" of GIF files is the limited palette - instead of supporting the full 2^24 colors, GIF uses only up to 256 different colors at a time. This allows each pixel to take up less space (only 1 byte instead of 3, before compression). GIF is mainly useful for images with a small number of colors, such as charts or icons. GIF is not recommended for photographs. GIF has two additional features: layers, which allow you to have more than 256 colors by layering two or more images with two different palettes (where the top layer has one "transparent" color, which lets you see the bottom layer), and animation, which simply lets you store a series of images inside the same file, which are played sequentially. This is mainly intended for use in simple short animation (like a blinking smiley face), not full on videos. The reason animated GIFs are commonly used in place of an actual video format is that until a few years ago, GIF was the only animated format that was supported on every possible platform.

PNG is a modern file format, intended to replace GIF. It uses non-lossy compression and supports the full color palette instead of just 256 colors. It also supports transparency (unlike JPEG). PNG images take up more space than JPEG, but they preserve the original image quality since the compression is non lossy.