A preformatted document that can be use as a starting point and then change to suit your needs

template

Explanation:

It is certainly the template. As an example, we can consider the mailing list in case of the mail merge. We can consider the mailing list as a template, as it is a preformatted document which one can use as a starting point and then we can make changes in it such that it suits our requirements. And our requirements can vary with time. Each time we will have new requirements, and we can make the changes in the mailing list to suit it. The web page design is also an example. We have numerous design templates to choose from while designing a web page. And we can use CSS, Bootstrap to make many such.