Aperture is an online art and image generator. It allows users to create custom images with the help of a tool called Lexica. They can choose from a variety of dimensions and settings to make the image look exactly how they want it. They can also use a prompt to help them come up with ideas for their image. Once they have chosen their settings, they can generate the image and save it for later or share it with others. Aperture also keeps track of the user's history and likes, so they can easily find images they have created in the past.