In Splunk Enterprise, everything revolves around search.
Note: This answer applies to Splunk Enterprise and Splunk Cloud.
Search Processing Language (SPL) is Splunk's query language used to express the search commands and their functions, arguments and clauses, which tell the Splunk software what to do to with the events you retrieve from the indexes. The Splunk Enterprise Search Manual is a great place to start building your SPL ninja skills.
Any search in Splunk Enterprise can be saved as a saved search, scheduled search, report, new dashboard, or a panel within an existing dashboard. Here are some terms to get you started:
I adjusted the question and a portion of the answer to better reflect that this is about the search screen and not limited to the search app.