Questions

A data dictionary is a special file that contains a set of information describing the contents, format, and structure of a database and the relationship between its elements, used to control access to and manipulation of the database.

Here the puzzle follows the logic that

Right side number = sum of the number on the left side and the previous number on the left side

=> 6 = 4+2

=> 10 = 6+4

=> ? = 16+10 = 26.

The main constituent of biogas is methane (55-70%), CO2 (30-45%) and some traces of gases such as H2S and ammonia.

Biogas is produced under anaerobic conditions; the process is denominated as anaerobic digestion.

Cache memory is an extremely fast memory type that stores data so that future requests for that data can be served faster. It acts as a buffer between RAM and the CPU. It holds frequently requested data and instructions so that they are immediately available to the CPU when needed.

The address resolution protocol (ARP) is used to associate the 32 bit IP address with the 48 bit physical address, used by a host or a router to find the physical address of another host on its network by sending a ARP query packet that includes the IP address of the receiver.

The reverse address resolution protocol (RARP) allows a host to discover its Internet address when it knows only its physical address