Questions

IP address is currently 4 bytes long. An IP address is written in "dotted decimal" notation, which is 4 sets of numbers separated by period each set representing 8-bit number ranging from (0-255).

Hydroelectricity is electricity produced from hydropower i.e, water.

A Light-year is a distance that light travels in the vacuum in one Julian year (365.25 days).

The light-year is a unit of length used to express astronomical distances. It is about 9.5 trillion kilometers or 5.9 trillion miles. 

A clipboard is a temporary storage area for items that the user wants to cut or copy from one place to another.

For example, in a word processor application, the user might want to cut text from one part of a document and paste it in another part of the document or somewhere else, it is temporarily stored in clipboard.