A Search builder is a feature (or an interface?) which can be used to do an advancedsearch in a bibliographic database.
A free text search can be done; but a search builder includes the possibility to search by individual fields of the record (keyword, subject, title, source title, author, etc.)
You can choose the field in a drop-down menu or you can use the field codes typing them before the words and according to the particular language of the database.
Other search options can be offered by a search builder, such as expanders and limiters. Examples of expanders are applying related words, searching in the full text of articles, and so on. Examples of limiters: by date or period, geographic regions, full text available, subjects, languages, and so on.
an advanced: if you agree, we can add this word - OK, G
either: are: apply related words, search in the full text
or: are applying related words, searching in the full text - OK, G