Definition:Â A collection of related data arranged in a way suitable for adding, locating, removing and modifying the data.
The database which store biological data is called biological database Eg: nucleotide sequence data base
 DNA sequence databases:
![EMBL EMBL](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhSAKQXkLHfXU3dhCO4i0Fru2ATV89b-vRMF_mo8__Yj263UgAgyYpEiONceJsRhOMC6rP9k5KTRQ2ePpYlxKg8ul8ak3j_fSn3HuTqVAmES9mGE0oQojNsSyBuhXaWkbRO8SwhJ_OIbY3f/?imgmax=800)
Protein databases:
The database which store biological data is called biological database Eg: nucleotide sequence data base
 DNA sequence databases:
- Genbank of (National Center For Biotechnology Information)
- DDBJ:DNA Data Bank of Japan
- EMBL/EBI: European Molecular Biology Laboratory/European Bioinformatics Institute
Protein databases:
- SWISS-PROT
- PIR: Protein Information Resource
- TREMBL: Translated EMBL
- PDB: Protein Data Bank