You input a couple of words. Then hit generate. In a few seconds, a dragon on a bicycle appears in Tokyo. It is not magic, it is mathematics. Crazy complicated mathematics, yet mathematics. Here is what is really going on. Millions of labeled images are used to train these tools. Over time, the model learns patterns - what fluffy means, how shadows behave, what gives a vintage feel. As you type your prompt, it re-creates something that conforms to those acquired patterns. It is not really drawing, but highly confident prediction.
What separates great results from average ones? wikipedia reference It is prompts. All so very ugly, yet true. Ask for a cat and you get a cat. A grumpy orange tabby on a rainy windowsill in oil painting style gives you something special. Crafting prompts is a real skill - even a paid profession.
Various tools approach this differently. Some tools focus on photorealism. Still others are bright with illustration or concept art. Some of them allow you to feed in an image of reference and tell you to make one like this but with dinosaurs. The variation is massive.
One of the things that confuse people: such generators do not think. They do not understand your intent. They only respond to what you input. Request a man holding a light and you could have a man holding a flashlight, a candle or a featherweight glowing ball. The issue is not the tool, but the vague input.
The elephant in the room that no one would like to feed is copyright. Who is the owner of AI-generated images? Regulations have not caught up yet. Some claim ownership, others grant it to users. Before monetizing, read the terms carefully.
The speed is astonishing. Work that needed hours of artistic effort can now be done in seconds. That does not mean that artists are bad. It is just another tool, like a typewriter evolving into a keyboard.
You can create mood boards, prototypes, book covers, game art, and social media visuals. Its use cases are expanding faster than expected. You no longer need to be a designer to bring ideas to life visually. That transformation is still settling in.