Any given Project you see will have a number of sections available, as shown below with Details, Description and Items being their own distinct sections.

You are able to modify which sections are Active, and where each section sits, via the Layout Menu. This can be found along the top of the project page, by clicking the three dot menu icon as found on the same row as the project title:

As well as activating/deactivating certain sections, you can also decide if each section should be expanded or collapsed as the default when the page loads. For instance, you could have a lot of job information stored in the description section and while this is useful and necessary, it takes up a lot of screen real estate. Deciding that it should be collapsed by default will mean whenever you load the page, it stays as a collapsed section header until you are ready to expand it/look at it further.