- 
  
  Vacuum tube technology
 Unreliable
 Supported machine language only
 Very costly
 Generated lot of heat
 Slow input and output devices
 Huge size
 Need of A.C.
- 
  
  Use of transistors Reliable in comparison to first generation computers Smaller size as compared to first generation computers Generated less heat as compared to first generation computers Consumed less electricity as compared to first generation computers Faster than first generation computers Still very costly A.C. needed
- 
  
  IC used
 More reliable in comparison to previous two generations
 Smaller size
 Generated less heat
 Faster
 Lesser maintenance
 Still costly
 A.C needed
 Consumed lesser electricity
- 
  
  VLSI technology used
 Very cheap
 Portable and reliable
 Use of PC's
 Very small size
 Pipeline processing
 No A.C. needed
 Concept of internet was introduced
 Great developments in the fields of networks
 Computers became easily available
- 
  
  ULSI technology Development of true artificial intelligence Development of Natural language processing Advancement in Parallel Processing Advancement in Superconductor technology More user friendly interfaces with multimedia features
