Suppose you have task which collects the data the from various sources and creates a Object containing all this information e.g. information is distributes over various databases, websites and some you need to calculate based on that data. The single threaded application works fine with small amount of data however as data starts growing single threads shows its limitation. There is a interesting property of threads which comes to our rescue. Thread maintains the private copy of object on which it operates called as w orking copy in which it keeps the local modification which are made to the object. While main memory contains the master copy of every object. After all threads stop executing all the working copies are merged into the master copy. This becomes the curse in case of multiple objects modify the same field in the object because merging back creates the confusion and results in a unpredictable behavior. However if each thread works on the different field of the object me
My Opinion.