Desktop databases
The first database systems were aimed at corporate customers and large organisations but as the popularity of personal computers rose many manufacturers began to produce scaled down versions which allowed anyone to create databases on their own computer.
Although not as powerful as the large scale databases (which are needed for some types of application) desktop databases like Microsoft® Office Access and many others are quite suitable for small or medium sized enterprises to develop databases on a single computer or shared database on an (ethernet) office network.
Their advantages are that they are very flexible, easy to deploy and maintain, and provide immediate access to your data.
What you get is not actually a database but a Database Management System (DBMS) which can create and run any number of databases. Usually the package also includes tools to help you, in particular there is usually a simple graphical interface to help you create tables and queries, work directly with your data or create forms and reports to automate data input and output. Most also include the option to add 'programming' - macros, or procedures - to process data or carry out repetitive jobs.
This means that there are a range of possibilities from creating a simple database using the tools provided and adding a few simple forms and reports and queries as required, right up to building a sophisticated information system with automated processes and separate user interfaces for many routine tasks.