Boolean operators are used in databases to combine terms and phrases. AND is used to combine terms and phrases so that all terms and phrases are contained in the results, OR is used to combine terms and phrases so that any term or phrase is contained in the results. Use AND to focus your search and OR to expand a concept.
Filters are pre-formatted searches that are applied to your search to focus your search to a specific set of information, i.e. English only articles, randomized controlled trials, last 10 years, etc.
Nesting is a convention used in databases to dictate the order of functions that a database search will run. All terms and phrases contained within parentheses (the nest) will be run as a complete separate searches before the database combines the two or more nests. I.e. the database will search (stroke OR cerebral vascular accident) and then (therapy OR rehabilitation) and then combine those two sets to give you your results, this is what it would like in the database: (stroke OR cerebral vascular accident) AND (therapy OR rehabilitation). Without nesting the search would not give you what you are looking for.
Search History refers to the area of the database that holds the results of all of your searches. You can use this area to combine different search results to create a complex search.
A search map is device that is used to strategize and organize the search you intend to run in a database. It is only needed for complex searches.