difference between meta language and markup language?

Question

I want to know the exact difference between markup language and meta language

As we know XML is extensible markup language but I read it is a meta language, so how can be define a meta language and a markup language ?

Answer 1

Markup language:-

A (document) markup language is a modern system for annotating a document in a way that is syntactically distinguishable from the text. The idea and terminology evolved from the "marking up" of paper manuscripts, i.e., the revision instructions by editors, traditionally written with a blue pencil on authors' manuscripts. In digital media this "blue pencil instruction text" was replaced by tags, that is, instructions are expressed directly by tags or "instruction text encapsulated by tags".

Metalanguage

metalanguage is language or symbols used when language itself is being discussed or examined.1 In logic and linguistics, a metalanguage is a language used to make statements about statements in another language (the object language). Expressions in a metalanguage are often distinguished from those in an object language by the use of italics, quotation marks, or writing on a separate line.