Despite the increased complexity and the difficulty of building distributed computing systems the use is rapidly increasing because the advantages of distributed computing systems outweigh their disadvantages. The major advantages that have led to emergence and popularity of distributed systems are:

i. Inherently Distributed Applications:

• Several applications are inherently distributed in nature and require distributed computing system for realization. These applications might have distributed locations for collecting, processing and accessing data resulting in need of distributed computing systems.
• Example: A computerized banking system.

ii. Information sharing among Distributed users:

• Another reason for emergence of distributed computing systems was the desire for efficient person-to-person communication facility by sharing information over distances. In distributed systems information generated by one user can be easily shared by other users for many ways.

iii. Resource Sharing:

• Sharing of software resources such as software libraries and databases can be done in an efficient way among the users of a single distributed computing system. Cloud storage can be an example.

iv. Better Price-Performance Ratio:

• This is one of the most important reasons for growing popularity as the increased power and reduced microprocessor price is combined with fast communication network that provide better price-performance ratio.
• Resource sharing is allowed in distributed computing which makes it cost-effective.

v. Shorter Response Time and higher Throughput:

• Multiplicity of processors enable distributed computing systems to have better performance. Most common performance metrics are response tine and throughput of user processes. Example is the workstation model where the users have multiple processes that run simultaneously and interact with each other.

vi. Higher Reliability:

• Reliability refers to the degree of tolerance against errors and component failures in a system. A reliable system prevents loss of information even in the event of component failure. The multiplicity of storage devices and processors in a distributed computing system allow the maintenance of multiple copies of information which still provide data if one site is down.

vii. Extensibility and Incremental Growth:

• It is possible to extend the power and functionality of a distributed computing system be adding additional resources to the system. Extensibility is also easier because addition of resources can be done without disruption of the normal functioning of the system.

viii. Better flexibility in Meeting Users Needs:

• A distributed computing system may have a pool of different types of computers from which the most appropriate one can be selected for processing a user’s job. Hybrid model can be an example for this.