Drawback of these electromechanical and mechanical computers

The basic drawback was:

• Inertia/friction of moving components had limited speed.
• The data movement using liner and gears was quite complex and unreliable.
• The change was to have storing and switching mechanism with no moving parts and then electronic switching technique "triode" vacuum tubes were used and hence born first electronic computer.
• The development of digital computing is often divided into generations. Each generation is characterized by vivid improvements over previous one in technology used to build computers, internal organization of computer systems and programming languages. Although not usually connected with computer generations, there has been a steady advancement in algorithms, including algorithms required in computational science. The following history has been prepared using these widely recognized generations as milestones.