Fonts serifSuch a font was created for the main text of books and newspapers.
To save money, newspapers and books are made from cheap paper (expensive books are used only for covers in books). On such paper, the small text is not always clearly printed, especially the edges. It was for this purpose that a serif font was created to mark the edges of the letters clearly. So all the letters are clearly distinguishable and read without tension. Therefore, every normal newspaper uses the Times headset for the main text.
Fonts CourierSuch a font was created for use on typewriters.
In the typewriter, the step is the same, because it was necessary to make all the characters (not just letters) of the same size. And the edges (serifs) do even more, because the typewriter was worse than the typewriter. So the underlining of the edges was reinforced. Today, such a font is used to computer for simple texts, where without unnecessary tweaks the letters of different lines lay flat under each other. Sometimes "patterns", faces were drawn in this way ...
Fonts sans serifsSuch a font was created for use by computer.
On the computer, everything is OK "printed" and there is no need in the notches, on the contrary, small details pollute the text and were unreadable. We needed a simple font so that one color would appear on every point of the screen - say black or white, no gray.
This text looks clear and better read to computer.
What about beautiful decorative and other fonts?Yes, there are many different fonts and for other purposes: for GOST or drafting, for posters ...
In addition, for titles of articles in the same newspaper or for the table of contents of the book, you can use any type of font that is appropriate. It is larger and will be well read in any case. By the way, solid newspapers choose a font for their headings and use one font for everyone. So the newspaper looks more stylish and more solid. Cheap newspapers ask each headline a new font. It looks rainy and somehow childish. Most likely this newspaper was a teenager.