Final answer:
The feature of EC2 that allows you to provide commands that the instance will run at startup is user-data.
Step-by-step explanation:
The feature of EC2 that allows you to provide commands that the instance will run at startup is user-data. You can specify these commands as a script or a cloud-init directive, which are executed when the instance is launched. This is useful for automating tasks such as installing software, configuring applications, or setting up the environment.