Which access method is least efficient for data retrieval?

Sequential access reads data from the beginning to find what you need. If the data is at the end, you must read through everything first. This is like listening to a cassette tape to find a specific song.

Direct access jumps straight to the location you want. Indexed and random access also allow quick retrieval. Sequential access wastes time reading unnecessary data.

Modern systems avoid sequential access when possible. Direct access methods are much faster for retrieving specific information.