What is the meaning of ,?

Separates items in a list.

Separates clauses in a sentence.

Separates coordinate adjectives.

Optionally sets off quoted material that is the grammatical object of an active verb of speaking or writing.

Separates one element in a date from another.

Separates a region from a geographic place within.

Separates the surname from the given name when the traditional order is the reverse.

Separates a title from a name.

Marks elision.

Sets off a noun or pronoun that represents someone or something being spoken to (when used independently).

Separates steps to do something in software.

A separator used with numbers.

  1. In some counting systems, separates groups of three consecutive digits; the thousands separator.

    In some counting systems, separates groups of three consecutive digits; the thousands separator.

    In the Indian numbering system, separates groups of two consecutive digits, except for one final group of three.

    In some counting systems, sets off the decimal or fractional part of a number; the decimal separator.

    the suffix -(V)nce or -(V)nse (-ance, -ence, -anse, -ense, etc.)

    the suffix -ity

    final glottal stop (on a syllable with fully falling lexical tone).

    High-falling lexical tone.

    glottal stop (with falling lexical tone).

    Source: wiktionary.org