These two databases are collections encyclopedias, dictionaries, and similar resources. Both are great places to look for background information about mythology topics.
Encyclopedias provide brief introductions to subjects - in these cases people, gods, legends, places objects, motifs, and other aspects of mythology and folklore. Entries are typically one or two pages long.
Dictionaries tend to offer very brief definitions and descriptions of subjects - in these cases people, gods, legends, places objects, motifs, and other aspects of mythology and folklore. Entries usually are only a paragraph long.