Db2 for z/OS and SQL concepts
Many structures and processes are associated with a relational database. The structures are the key components of a Db2 database system, and the processes are the interactions that occur when applications access the database system.
In a relational database, data is perceived to exist in one or more tables. Each table contains a specific number of columns and a number of unordered rows. Each column in a table is related in some way to the other columns. Thinking of the data as a collection of tables gives you an easy way to visualize the data that is stored in a Db2 database.
Tables are at the core of a Db2 database. However, a Db2 database involves more than just a collection of tables; a Db2 database also involves other objects, such as views and indexes, and larger data containers, such as table spaces.
With Db2 for z/OS and the other Db2 products, you can define and manipulate your data by using structured query language (SQL). SQL is the standard language for accessing data in relational databases.