Using limits narrows a search and decreases search results. Searches may be limited by publication year, publication type, language, location, age groups, and material format. Limiting options vary from database to database. It is a good idea to apply limit options one at a time. Remember! The more limits you apply, the more you decrease your search results (demo: team teaching search in ERIC).
Reasons for limiting
Limit results by publication year when currency is an important aspect of your research project.
from 2006 to 2012
Limit results to the material type, articles, when your research project requires an emphasis on the journal literature.
Limit results to only those languages you can read.