Most databases and search engines have a simple search bar on their home page. In this search bar you can enter a single search term, or you can combine search terms, for example:
school AND amsterdam
Usually there are also more extensive options. These can be found under advanced search. This is also called advanced search or multi-field search.
With advanced search you can formulate your search query much more precisely, combine or exclude terms. You can enter more search terms at once, in different search fields.
Example: Advanced search in CataloguePlus