Difference between centralized and distributed computing

Question

Can anyone tell me the differences between centralized and distributed computing?

Answer 1

Main basic differences are:

• distrib-systems have no global state
  • no shared memory
  • no shared variables
• distrib-systems have no shared time clock
  • therefore order of events is difficult
• distrib-systems can have race conditions
  • race conditions see http://en.wikipedia.org/wiki/Race_condition

So "computing" in a distrubuted environment is very difficult. Do you have concret question about programing models or whatever?

Answer 2

Centralized: all calculations are done on one particular computer (system). Example: you have a dedicated server for calculating data.

Distributed: the calculation is distributed to multiple computers. Example: when you have a large amount of data then you can divide it and send each part to particular computers which will make the calculations for their part.