You cannot use an external database for your Salesforce data, if that's what you're asking. Salesforce data (for Accounts, Contacts, Opportunities, etc.) is housed on the Salesforce platform.
However, using an integration service (or web-services, REST API, etc.), you can connect or sync to an external database.
You cannot use an external database for your Salesforce data, if that's what you're asking. Salesforce data (for Accounts, Contacts, Opportunities, etc.) is housed on the Salesforce platform.
However, using an integration service (or web-services, REST API, etc.), you can connect or sync to an external database.
Here's a list of integration services:
Information on other tools, to integrate Salesforce with other databases, is available here: