The Library's electronic resources are databases (and sometimes database is in the title of the resource - for example, Education Database as below)
A database is a collection of related information arranged into individual records and easily searched by a computer. Each record has different fields, such as title, abstract, authors, publication dates etc. The content of these fields will be different for each record, but the type of data is the same - the title field contains the title, the author field contains the authors etc.
Databases have rows and columns like an Excel spreadsheet. A row in a library database would be the content of an individual article that is split by fields, with each row containing individual pieces of data that are common across all records (such as title, author, publication year - called fields). A column in a database would be a field name. Here's a record from Education Database.
You can see the fields (abstract, subject, title, author etc) and the content and the record has been formatted to make it more readable
The basic search option usually searches the entire database or in the advanced search you can narrow your search to specific fields. Searching by specific fields is a good way of reducing the number of search results if you're getting too many search results
Search engines like Google are databases and are searched in the same way.