23. Write about your understanding of databases.

According to oracle.com (2023). A database is a systematic collection of information or data that is often stored in a computer system. Typically, a database management (DBMS) system is in charge of managing a database. A database system, frequently abbreviated to just database, is the collective term for the data, the DBMS, and the applications that are connected to it.

Advantages of databases. (Sahana 2022)

1. Improves Data Security.
2. Reduces data redundancy.
3. Reduces operating cost.
4. Enhances Data Access.

Disadvantages of databases. (geeks4geeks.com 2023)

1. Security may be compromised without good controls.
2. Integrity may be compromised without good controls.
3. Extra hardware may be required.
4. Performance overhead may be significant.
5. The system is likely to be complex.

Primary Key. (Ian 2016)

A primary key is one or more columns that have been set up as the table's special identification field.

The majority of primary keys consist of a single column, but they can also have numerous columns.

Any information kept in a field's primary key is specific to that record. That value is not found in any other record. A special identifier serves as the value.

Foreign Key. (Ian 2016)

A foreign key is a field that is linked to the primary key field of another table in a relationship between two tables.

An association between two or more tables is defined by a relationship in relational database management systems. That is, the information in one table is connected to that in another. The foreign key is contained in one table while the primary key is in the other table.