Overview:
Permanent data and instructions are stored in ROM (Read-Only Memory) chips. Unlike RAM (Random Access Memory) chips and DRAM (Dynamic Random Access Memory) chips, ROM chips retain data even when the power is turned off. This makes them suitable for storing essential system instructions and other permanent data.

Explanation:
ROM chips are non-volatile memory devices that are responsible for storing permanent data and instructions. They are designed to retain data even when the power supply is disconnected, making them ideal for storing essential instructions that need to be available at all times.

Differences between RAM, DRAM, and ROM:
1. RAM (Random Access Memory):
- RAM is a type of volatile memory that stores data and instructions temporarily while the computer is running.
- It provides fast access to data, allowing the CPU to read and write information quickly.
- However, RAM requires a constant power supply to retain data. When the power is turned off, the data stored in RAM is lost.

2. DRAM (Dynamic Random Access Memory):
- DRAM is a type of RAM that stores data in capacitors within memory cells.
- It needs to be refreshed periodically to maintain the stored data, which requires additional circuitry.
- Similar to RAM, DRAM is volatile and loses its data when the power is turned off.

3. ROM (Read-Only Memory):
- ROM is a non-volatile memory that stores data and instructions permanently.
- It is manufactured with pre-programmed data and cannot be modified or erased by normal computer operations.
- ROM retains its data even when the power is turned off, making it suitable for storing critical instructions necessary for booting up the system and initializing hardware.

Conclusion:
In summary, ROM chips are responsible for storing permanent data and instructions. Unlike RAM and DRAM, ROM retains its data even when the power is turned off, making it ideal for storing essential system instructions and other permanent data.