Delta-Parquet is the same as parquet type (Compressed) with the addition of its underlying storage, adds metadata for features like ACID transactions, versioning, and schema enforcement. This allows for transactional operations like updates, deletes, and merges, while still maintaining the benefits of Parquet's columnar storage for efficient querying.

The Delta-Parquet file has been used where required to manage the history.

If you compare these 2 types, then parquet has been used while you need to interact with Gold(final) data value.

Delta-parquet occupies more space than the parquet format.