Question

Let's consider a space, or a tab or a carriage return. What are each of them referred to?

Answer 1

They are referred as white spaces in c and c++ languages. In computer programming white spaces are for horizontal or vertical spaces in typography
white space is not similar to visible mark and is not occupy are on a page 
white space character can be inserted using a space bar button on the keyboard
hope this answer is useful and can suffice your question 

Answer 2

A space, a tab, and a carriage return are all used in formatting. So, each of them can be called a formatting character.

A space represents the blank character between two words. This is also known as a white space. Two other types of spacing that are commonly used are line spacing (the line between two paragraphs) and paragraph spacing (the space between two paragraphs). 

A tab helps in the alignment of numerical data or text with respect to the margins set for a document.

A carriage return denotes the characters at the end of a record. It also creates a line break in order to automatically line the cursor with the left margin to start a new paragraph. In computers, the Enter key provides the carriage return functionality.