Answer:
These are called hyperlinks. A programming language called is responsible for these existing. It stands for hypertext markup language. It can also be used to link documents to each other through these hyperlinks.
From scientists planing to share information across countries. Letters and the mail system took to long for certain situations.
The "middle" of a sorted list of numbers
You can insert a new slide in power point by pressing CTRL + M
CTRL + I = to write in italic letters
CTRL + N = New presentation
CTRL + Home = move to the beginning of text box