What is a database? A collection of records. What is a database management system? A means specially crafted to manage all the records. It is a software system that makes use of a standard method along with some queries on running them. These queries are designed to administer and control the databases properly. In short, you can say it is software that is used to manage proper functioning of the databases to provide a systematic way to create, retrieve, manage and update data stored in those databases.

Database Management Systems are of various types and they are classified on various aspects as given in the figure below-

Based on Data Model
Keeping Data Model as the criteria there are three types of DBMS systems

Relational Database
It is a table-oriented database which means that all the data is stored in various access control tables and every one of these tables has a key field whose primary task is to identify each row within that table. These tables or we can say the files with which the data is attached are called as relations and these relations are what helps in designating the rows or records, and the columns of these tables are referred to as the attributes or fields in RDBMS.

Hierarchical Database
This is a database management system where the data is commanded by the database administrator in a way that follows a specified series of records as well as the set of values attached to that particular record. This type of DBMS is widely used in industries on mainframe platforms.

Object-Oriented Database
This is database management system in which the information is stored in the form of an object as it is done in several object-oriented programming techniques. This type of database adds an added advantage of giving database functionality to the object programming languages running the DBMS.

Based on Number of Users
Keeping the number of users operating the database system as the criteria there are two types of DBMS systems

Single user
As the name itself depicts this type of DBMS can bolster only one single user at any given point in time. These types of database management systems are usually installed on personal computers wherein the data is deemed to be accessible to one single user only. This user may configure, design, upgrade or write database programs on this DBMS.

Multiple users
This type of database is empowered and designed to support multiple users at the same point in time. With this type of database, you can have your data integrated as well as shared. This because a database needs to be integrated when there is a requirement of same information to multiple users as this avoids data duplicity and frees up space.

Based on the sites over which network is distributed

Keeping Data Model as the criteria there are three types of DBMS systems

Centralized database system
When the Database Management System and the database are stored at one single site which is simultaneously being used by various other systems too is a typical definition of what a centralized DBMS system is.

Parallel network database system
This is one of the best database management systems as it provides an advantage of enhancing the processing input as well as the output speeds. Chiefly used for processing the applications that have got many queries pertaining to a larger database.

Distributed database system
This type of database management system is a typical example of distributing the DBMS software over several sites but in the end, the databases are connected to one single computer.

Conclusion
Database Management Systems play a very important role in the world of databases. They are like guardian angels protecting your data at your terms. The best part is that there are so many types of Database Management Systems available that you can easily shortlist the one that fits all your needs and have an administrator take care of it.