The About page of your GPT helps users in the GPT Store more easily learn about your GPT. This will include your GPT name, profile picture, and description, as well as information like the GPT’s rating, category, capabilities, starter prompts, Builder information, and other GPTs by the same builder.
You can customize these fields in the "Configure" tab of the GPT editor and in the Builder Profile. The "Category" can be modified under the "Save" dropdown of your GPT.
Example About page for the Wolfram GPT: