Banco de dados vs. base de dados
In Portuguese, the English word "database" can be translated as either banco de dados or base de dados. While they are technically synonyms referring to an organized collection of data, the primary difference is regional. Banco de dados is the standard term in Brazilian Portuguese, whereas base de dados is the standard in European Portuguese (Portugal) and Africa. In some technical contexts within Brazil, base de dados may specifically refer to the raw collection of information (a dataset) rather than the software system managing it.
Banco de dados
B2This is the predominant term used in Brazil to refer to a database. It implies both the storage system (software) and the data itself. If you are speaking with a Brazilian software engineer, this is the term they will likely use for the technical infrastructure.
O servidor caiu e não consigo acessar o banco de dados.
(The server crashed and I cannot access the database.)
Você precisa fazer um backup do banco de dados todos os dias.
(You need to make a backup of the database every day.)
Eles contrataram um especialista em banco de dados para otimizar o sistema.
(They hired a database specialist to optimize the system.)
A migração do banco de dados para a nuvem foi um sucesso.
(The migration of the database to the cloud was a success.)
Base de dados
B2This is the standard term in Portugal, Angola, and Mozambique. However, it is also used in Brazil to refer specifically to a logical set of data, such as a list of customers, a bibliography, or a statistical dataset, rather than the technical management system.
A polícia consultou a base de dados de impressões digitais.
(The police consulted the fingerprint database.)
Nós compramos uma base de dados com mil contatos de email.
(We bought a database with one thousand email contacts.)
Esta pesquisa utiliza a base de dados do governo federal.
(This research uses the federal government's database.)
Em Portugal, toda empresa deve registrar sua base de dados.
(In Portugal, every company must register its database.)
Summary
To sound natural, use banco de dados when speaking Brazilian Portuguese, especially regarding IT infrastructure. Use base de dados when speaking European Portuguese or when referring specifically to a collection of information (like a dataset or mailing list) rather than the software system.