Explanation

• Bluetooth is a Personal Area Network (PAN) technology used for short-range communication.
• It connects devices within a range of about 10 meters.
• It is commonly used in headphones, mobile phones, and laptops.
• It works without cables using wireless signals.

Last verified on 24-06-2026

Explanation

• Phishing is a cybercrime where fake emails, messages, or websites are used to steal sensitive information like passwords or bank details.
• It tricks users into believing the message is from a trusted source.
• Criminals often use social media, email, or SMS for phishing attacks.
• The main goal is identity theft or financial fraud.

Last verified on 21-06-2026

Explanation

• A firewall’s main function is to prevent or block unauthorized access to a computer network.
• It acts as a security barrier between trusted and untrusted networks (like the internet).
• It filters incoming and outgoing network traffic based on security rules.
• It helps protect systems from hackers and unwanted access attempts.

Last verified on 10-06-2026

Explanation

• A Foreign Key is a field in one table that refers to the Primary Key of another table.
• It is used to create a relationship between two database tables.
• A foreign key helps maintain referential integrity by ensuring valid data links.

Additional information:

• Primary Key: Uniquely identifies each record in a table.
• Candidate Key: A field that can become a primary key.
• Composite Key: A key made from two or more columns.
• Super Key: One or more columns that uniquely identify a record.

Last verified on 06-07-2026

Explanation

• Compiler Function: Converts high-level language into machine language.
• Output: Produces an object file (.obj / .exe) after compilation.
• Examples of Languages Using Compiler: C, C++, Java (uses compiler + JVM).

Additional information:

• Compiler: Translates whole program at once.
• Interpreter: Translates line by line.

Last verified on 21-02-2026