Text-to-image turns a written description into a picture.
The bridge between the two is a shared representation of text and images.
CLIP built that by training on hundreds of millions of image and caption pairs.
A text encoder turns the prompt into vectors in that shared space.
Those vectors condition the denoising at every step through cross-attention.
So the prompt is not consulted once but continuously as the image forms.
Guidance scale decides how hard the prompt pulls.
Classifier-free guidance runs the model with and without the prompt and amplifies the difference.
Around seven is typical, and above twelve images turn rigid and over-saturated.
Negative prompts describe what to avoid and are subtracted the same way.
Prompts work best when concrete, since a specific noun beats an adjective.
Style, medium, lighting and composition are the levers that change results most.
Known weaknesses persist: hands, text within images, and counting objects.
Spatial relationships are unreliable, since a red cube on a blue sphere often comes out reversed.
The training data was scraped, which is why copyright and consent remain live questions.