Delimiters are marks which are used to seperate subfields of data. 

These marks can be made of one or more characters. Also there can be multiple marks indicating the start and end points of specific data subfield and/or type.

 In the simplest form a delimiter is a monomorphic mark to divide a linear data chunk. 

The term delimiter refers to a separating character. In the following text, semicolons are used as delimiters between the numbers: A semicolon ( ; ) is a type of punctuation mark. ...

 123;234;123;3454353;3453; 

Delimiters are commonly used in computer files to separate data values. For example, the comma-separated values (CSV) file format uses a comma as the delimiter between fields, and a newline character as the delimiter between records. A computer file is a collection of information that is stored in a computer system and can be identified and referenced in its entirety by a unique name. ... The comma-separated values (CSV) file format is a tabular data format that has fields separated by the comma character and quoted by the double quote character. ... A file format is a particular way to encode information for storage in a computer file. ... The term comma has various uses; comma is the name used for one of the punctuation symbols: , The term comma is also used in music theory for various small intervals that arise as differences between approximately equal intervals. ... In computer science, data that has several parts can be divided into fields. ... In computing, a newline is a special character or sequence of characters signifying the end of a line of text. ...

One of the most interesting problems with using delimiters is the fact that often, data might use the character chosen as a delimiter. Consider a spreadsheet with the following values:

When saved to a CSV, the resulting file would include the line:

 Fred,Laura,Fred,Laura 

If you reopened the CSV file in the spreadsheet there would be four columns instead of the desired three.

Confusing data values with delimiters is quite a problem, with numerous solutions. One of the most common is escape characters.

Another common use of delimiters is to denote versions of computer programs. For example, software version 1.7.1 would denote the first major build of the program, with the seventh major software patch, and the first minor bugfix of that patch.

For word delimiters used in written languages, see interword separation. Interword separation is the set of symbol or spacing conventions used by the orthography of a script to separate words. ...