What do you call a text that tells how to something?

There are a few terms you could use to describe a text that tells how to do something, depending on the specific context and level of formality:

General terms:

* Instructions: This is the most common and general term for a text that tells you how to do something.

* Guide: Similar to "instructions," but often implies a more comprehensive and detailed explanation.

* Tutorial: A more informal term, often used for step-by-step guides that might include visuals.

* Manual: Typically refers to a comprehensive set of instructions for a specific product or device.

More specific terms:

* Recipe: Used for instructions on how to prepare food.

* How-to: A more informal term, often used for articles or videos that provide instructions.

* Handbook: A detailed guide that covers a specific subject or area.

* Protocol: A set of specific procedures or instructions, especially in a scientific or technical context.

The best term to use will depend on the specific content of the text and the intended audience.