Fundamental capabilities and limitations of computers:

• Versatility is a core characteristic; computers can execute diverse tasks from numerical calculations to multimedia processing.
• Accuracy is a hallmark trait; computer calculations are consistently precise and error-free unless incorrect data is input (GIGO).
• Diligence is a defining characteristic; computers never suffer from human fatigue, boredom, or loss of concentration.
• I.Q. (Intelligence Quotient) is NOT a characteristic of computers; a computer has zero native I.Q. and cannot take decisions without programmed instructions.

Hardware evolution leading to personal computers:

• PDAs (Personal Digital Assistants) were handheld devices developed much later in the 1990s.
• The invention of the single-chip Microprocessor (starting with Intel 4004 in $1971$) integrated the entire CPU onto a single silicon semiconductor chip, dramatically reducing manufacturing costs and enabling affordable microcomputers/PCs.
• Microcomputers are the resulting product, not the underlying invention.
• Mainframes were large, expensive multi-user systems of the 1950s-1970s.