Database (DB) is a collection of information of any subject area, organized according to specific rules and maintained in computer memory. There is no single definition of this term, but there are the following distinctive features of a database: it is stored and also processed in computer systems, data in a database has a logical structure, in a database there is metadata that describes its structure.
Instructions
Step 1
The simplest examples are car databases (store), higher education databases (reference book), product databases (warehouse), etc. One of the central points of any database is the data model it uses. It includes the structure of data in the database, their relationships and methods of communication with each other, as well as operations on them. There are three types of data models: hierarchical model, network, relational.
Step 2
The essence of the hierarchical structure is as follows. Database items at one level are subordinate to items at another level. The links between the elements as a result form the structure of the tree plan. Those. the following happens: the elements that are the original give rise to new elements, and those, in turn, are even newer. An important feature is that any element can only have one parent. A great example of a hierarchical data model is the family tree.
Step 3
In network structures, any child element can have more than one generator. The main difference between a network structure and a hierarchical one is that any element in the network model has a relationship with every other element of it. An example of a networked database would be a database that contains information about students attending classes for specific instructors. One student can attend the subjects of different teachers, and different students can come to the same teacher.
Step 4
A relational database is one that can be represented as a two-dimensional array. The idea is to represent arbitrary relationships between elements in a two-dimensional table. An example would be a table that will contain information about students. One line will correspond to one student, i.e. be one piece of data. The columns will contain information about the students, for example, name, date of birth, address, etc.
Step 5
A database management system (DBMS) is a specialized software required for database creation, maintenance and support. DBMS are able to enter information into the database, edit it, search and carry out other operations. Examples include Microsoft Access, MySQL, Microsoft SQL Server, Paradox, Oracle, etc.
