First generation computers were developed between the 1940s and early 1950s. They used vacuum tubes for circuitry and magnetic drums for memory. These machines were large, expensive, and consumed a lot of electricity, making them impractical for personal use. Notable examples include the ENIAC and UNIVAC, which were primarily used for scientific calculations and data processing. Programming these computers was complex, often requiring machine language or assembly language. They had limited capabilities and were not user-friendly, as they lacked operating systems and relied on punched cards for input. Despite their limitations, first generation computers laid the groundwork for future advancements in computing technology.