An online database is a database accessible from a local network or the Internet, as opposed to one that is stored locally on an individual computer or its attached storage (such as a CD). Online databases are hosted on websites, made available as software as a service products accessible via a web browser. They may be free or require payment, such as by a monthly subscription. Some have enhanced features such as collaborative editing and email notification.
A cloud database is a database that is run on and accessed via the Internet, rather than locally. So, rather than keep a customer information database at one location, a business may choose to have it hosted on the Internet so that all its departments or divisions can access and update it. Most database services offer web-based consoles, which the end user can use to provision and configure database instances.
As internet becoming more and more accessible to the worldwide. Many "pirate" databases (e.g. Z-library) are established by individuals or institutions. The debate of piracy is a constant topic for many decades. But this time, the "battlefield" shifts to the internet.