| A full stop is the same thing as a period that appears at the end of a sentence and is a longer pause than a comma. Like that or this. The full stop is one of the three ways to end a sentence (the other two being an exclamation mark or question mark). As I understand it, all punctuation that causes a pause was at one time considered a stop - the period being the longest pause was a full stop.
A full stop is also found following an abbreviation is also
a full stop. Examples of such usage include "Dr." and "Mt." The full stop is not necessary after a full stop that is part of an abbreviation and finishes the sentence. An example of this usage can be seen in the first sentence of the paragraph along with "I own Foo Inc."
An exception to the use of a full stop following abbreviations exists when the abbreviation ends with the same letter as the last letter of the word - "Mr" and "St" are two examples of this. Furthermore, if the abbreviation is one of a well known institutions, such as WHO, no full stop is necessary.
The full stop itself dates back to antiquity where it was used in Rome to separate words and phrases. Its use can be found in Ovid (though he used them sparingly and preferred colons and semi-colons to separate sentences; a full stop was a entire change of subject).
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