What is print that is very dark called?

Why do authors use bold print or italics?

A picture that explains something is called (usually has arrows and words)

the title at the top of a paragraph or groups of paragraphs is called...

An author uses headings to show -

Authors use this feature to explain what they they want the reader to notice in a photograph or illustration

Letters that are slanted that are used to show important words are called

information/words that is organized in a set of square boxes or rectangles

this feature is used to show when something happened

this feature is used to show where something is

A numbered list is used to show

extra information set apart in a square or circle