A Boot Sector Virus infects the master boot record (MBR) of a storage device, making it one of the most challenging and complex types of viruses to remove. It can load into memory during system boot-up, making it hard to detect and eliminate without specialized tools.

Communication between a computer and a keyboard is simplex, as the data flows in only one direction — from the keyboard to the computer. The computer does not send any data back to the keyboard during this interaction.

For GPS (Global Positioning System), at least three satellites are needed to determine a location on the Earth's surface (2D fix). To calculate a 3D fix (latitude, longitude, and altitude), at least four satellites are required. This ensures accurate positioning and elevation data.

Ray Tomlinson is known as the "father of email" because he implemented the first email system on the ARPANET (the precursor to the internet) in 1971. He also introduced the use of the "@" symbol to separate the user name from the host name in email addresses.

In the mail merge process, the steps include identifying the main document, linking it to a data source, and previewing the merge results. However, formatting the data source is not a required step in the mail merge process. The data source should already be organized before starting the merge.