A Virtual Private Network (VPN) is a technology that allows users to create a secure and encrypted connection to another network over the internet. VPNs are commonly used to ensure privacy and security when browsing the internet, especially when using public Wi-Fi networks. VPNs create a private tunnel for data transmission, protecting users' online activities from surveillance, censorship, and potential cyber threats.

1. To send an email, the sender's email address is mandatory. An email address is a unique identifier that connects an email message to a specific user.

2. Other required information for sending the email includes-

- Recipient's Email Address

- The subject of the email

The following devices are used to transmit network data.

- Microwave (Microweb)

- Infrared

- Radio Channel

1. Optical fibres use total internal reflection to transfer data. The primary condition for total internal reflection is that the signal must travel from an optically denser medium to an optically rarer medium. Secondly, the angle of incidence must be greater than the critical angle.

1. Personal email account Microsoft Exchange is usually used to download e-mail to your computer.

2. Microsoft Exchange Server is Microsoft's email, calendaring, contacts, scheduling, and collaboration platform.

3. It is deployed on the Windows Server operating system (OS) for business use.

4. Microsoft designed Exchange Server to provide users with access to the messaging platform from mobile devices, desktops, and web-based systems.

1. Extensions are called top-level domains.

2. File extensions are used so that the computer's operating system or OS can recognize the file type.

3. A file extension primarily refers to a suffix added to the end of a computer file (an object containing information, data or commands) to define the file type.

1. Through hyper link you can connect any location of the current document to another document or website.

2. Hypers are found in almost all web pages. Links allow users to click from one page to another.

The search engine performs the following tasks-

1. Web crawling: Search engines search all web pages on the web using a crawler. A crawler is a program that finds new web pages by following links on the web.

2. Indexing: Once the crawler finds all the web pages, the search engine indexes them in a database. The index contains information for each web page, such as title, URL, and content.

3. Searching: When a user types a search query, the search engine searches all the web pages in the index that may be related to the query.