| this is what most people would consider to be "normal" text. Consecutive lines of text have the least amount of space between them allowed for readability.
When people write huge blocks of single spaced text (in email, on everything, or in a long document), it can be difficult to read. Solutions to this include manually placing a lot of blank lines throughout the text (such as the blank line between the previous block of text and this one), double spacing, and probably more techniques that I can't think of right now. | 
