Explanation

• USB stands for Universal Serial Bus.
• USB is a standard used to connect and transfer data between electronic devices.
• A USB flash drive is a data storage device that uses flash memory with an integrated USB interface.
• Ajay Bhatt is widely credited as a key figure in the development of USB technology in the 1990s.

Last verified on 05-09-2026

Explanation

• TCL stands for Transaction Control Language.
• It is a part of SQL (Structured Query Language).
• TCL is used to manage transactions in a database.
• Common TCL commands include COMMIT, ROLLBACK, and SAVEPOINT.

Last verified on 05-09-2026

Explanation

• SIM stands for Subscriber Identity Module.
• A SIM card securely stores the subscriber's identity and enables access to a mobile network.

Additional information:

• First SIM card developed: 1991
• Invented in: Munich, Germany
• Manufacturer: Giesecke+Devrient (G+D)
• PIN: Personal Identification Number
• PUK: Personal Unblocking Key

Last verified on 22-07-2026

Explanation

• ROM stands for Read Only Memory.
• It is a type of non-volatile memory.
• So its contents are retained when power is turned off.
• ROM stores important instructions such as firmware and boot instructions.

Additional information:

• RAM → Random Access Memory
• PROM → Programmable Read Only Memory
• EPROM → Erasable Programmable Read Only Memory

Last verified on 08-08-2026

Explanation

• WAN stands for Wide Area Network.
• It covers a large geographical area, potentially across countries or the whole globe.

Additional information:

• LAN: Local Area Network covers a small area.
• MAN: Metropolitan Area Network generally covers a city.

Last verified on 03-09-2026