system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5 how do cameras capture a literal moment in time?
gpt
On film: you hit the button, and the shutter closes. When it does, it streams light through in a focused beam, and whatever light enters the aperture gets burned (for lack of a better term) onto the film. And that's a picture. 

On digital: same basic concept, but the light hits photosensitive tiles that convert the light into code - different colors and brightness are different pieces of the code. It stores this code and reproduces it on demand, making the picture you just took.