If you provide a service for a website, such as creating the site, performing SEO, writing content, or another task, you may be asked to sign a contract.
Often these contracts are general with nothing to be concerned about. But sometimes there is, such as a noncompete term.
For this industry, in most situations signing an agreement with a noncompete is not recommended. You would have to be paid a lot of money to suddenly not being able to create a site in a niche, or...