How does an index work and why does it make data transfer faster?

An index is a data structure that allows for quick retrieval of records without scanning all data.

Why data is transmitted faster thanks to an index:

• The index contains ordered or specially organized information about the data's location.
• Instead of sequentially scanning the entire table or array, searching by index allows you to immediately jump to the needed location.
• This reduces the number of input/output operations and computations.

For example, in a database, an index on the "ID" column allows you to quickly find a record with the required ID without scanning all rows.

In Java, for instance, an index can be implemented through data structures such as trees or hash tables, which provide fast access by key.