The period, also called full stop is one of the most common punctuation marks, this is used at the end of text, paragraphs or ideas to introduce a long pause and mark complete thoughts, But besides this use, the period is also used as part of ellipsis (...), in numbers and to abbreviate words which refers to shortening words, in this case most abbreviations that include the first/last letters of a word should end with a period and in some cases abbreviations that only use initial letters also include period. For example, the word "Mister" is commonly abbreviated as "Mr.", the word "December" is abbreviated as "Dec." and the term "United States of America" can be abbreviated as "U.S.A." Therefore, it can be concluded a period is also used to abbreviate words.
