Can you explain how data deduplication works and what it is used for?

Data deduplication is the process of identifying and eliminating duplicate data fragments to save storage space and improve data transfer efficiency.

Working principle:

• The system divides data into blocks (of fixed or variable size).
• Each block is hashed (for example, using SHA-256) to obtain a unique identifier.
• If the hash of a new block matches an existing one, the system does not store the duplicate block but uses a reference to the already stored one.

Deduplication is used in backup systems, cloud storage, and file systems to reduce the volume of stored data and lower storage and transfer costs.

Example: if you have 10 copies of the same file, deduplication will save only one copy of the data, and the others will reference it.