There are two ways to save a completed analysis for future reference.
Add to Dashboard
From a dashboard, click on any widget title to open the underlying query.
Dashboards are covered in greater detail in the Dashboards section.
Name and save your analysis by selecting "Add a Bookmark" above the Data Panel. This feature allows you to save the analyses you create to access or update later. Bookmarks can be created in all tools.
To find or open a bookmarked analysis, click on the bookmark icon in the tool sidebar. Here you can search for bookmarks, rename them, and open them in the tool.
Bookmarks are covered greater detail in the Bookmarks section.