Assuming you're talking about tape storage.. mainly speed ! With sequential access, the medium has to be constantly rewound back to the start before the next relevant data can be accessed. The constant rewinding slows down the access time.
random access memory
Random Access Memory
Magnetoresistive Random Access Memory
Random access memory.
Random Access Memory
Random Access Memory.
RAM: random access memory
synchronous access.
Random Access & Sequential Access
Advantages: One of the cheapest forms of data storage. Disadvantage: low density (bulky), not random access (slow).
used for a smaller population
This is done as because you can access the memory at any random point i-e randomly.