For example a DBMS has selected a specific File organization for the storage of data on disk, to implement that specific file system the DBMS needs to create specific indexes. Now whenever the DBMS will attempt to retrieve the data back form the file organization system it will use the same indexes information for data retrieval. This index information is one example of additional information which DBMS places in the data when storing it on the disk. At the same level storage space utilization if performed so that the data can be stored by consuming minimum space, for this purpose the data compression can be performed, this space optimization is achieved in such a way that the performance of retrieval and storage process is not compromised. Another important consideration for the storage of data at the internal level is that the data should be stored in such a way that it is secure and does not involve any security risks. For this purpose different data encryption algorithms may be used. Lines below detail further tidbits of the internal level.

The difference between the internal level and the external level demarcates a boundary between these two layers, now what is that difference, it in fact is based on the access or responsibility of the DBMS for the representation of data. At the internal Level the records are presented in the format that are in match with schema definition of the records, whereas at the physical level the data is not strictly in record format, rather it is  in character format., means the rules identified by the schema of the record are not enforced at this level. Once the data has been transported to the physical level it is then managed by the operating system. Operating system at that level uses its own data storage utilities to place the data on disk.

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