Science~12 min read
Computer applications
Hardware, memory, OS, networks, Internet, shortcuts.
- Generations: I vacuum tubes, II transistors, III ICs, IV microprocessors, V AI/ULSI.
- CPU: ALU + CU + registers. Fetch–decode–execute. Motherboard connects CPU, RAM, buses, slots.
- Memory hierarchy: registers → cache → RAM → SSD/HDD → optical/tape. Bit–byte–KB–MB–GB–TB (1024 steps in binary).
- Software: system (OS, drivers) vs application vs utility. OS functions: process, memory, file, device, security.
- Networks: PAN/LAN/MAN/WAN. Topologies: bus, star, ring, mesh. Devices: hub (L1), switch (L2), router (L3).
- Protocols: HTTP/HTTPS, FTP, SMTP, IMAP, TCP/IP, UDP, DNS. IP address identifies host; MAC is NIC hardware.
- Shortcuts: Ctrl+C/V/X/Z/S/P/A; Alt+Tab; Ctrl+Shift+Esc (Task Manager). Full forms: CPU, RAM, ROM, BIOS, URL, HTML, SQL, PDF, GUI, USB.
Video Lectures & Explanations
Curated educational video lectures explaining this topic for UPSC EPFO