What is a software? Mention the types of software with examples. What is meant by primary memory? Explain their types briefly.

Software is programs, data and procedures telling hardware what to do.

Types:

1. System software — Manages hardware: OS (Windows, Linux), compilers (C++), interpreters (Python), drivers (printer), utilities (antivirus, backup).
2. Application software — User tasks: general (Word, Excel, browser) and customized (hospital patient-record system, payroll).
3. Firmware — Code in chips: BIOS, router firmware.

Primary memory is CPU-directly-accessible temporary working storage (volatile except ROM), faster than SSD but smaller.

Types:

1. RAM — Read-write working space for OS + open apps. SRAM (fast, cache) vs DRAM/DDR (main 8–16 GB). Lost on power off.
2. ROM — Read-only startup code. PROM/EPROM/EEPROM/Flash; holds BIOS/UEFI that boots the OS.
3. Cache — L1/L2/L3 SRAM between CPU and RAM for most-used data; smallest-fastest (L1) to larger-shared (L3).

Hospital example: 16 GB RAM runs patient DB + billing together; SSD stores records permanently, RAM works on today's patients.