# JSON, XML, & YAML **Data serialization** is the process of converting data into a serialized format/structure that can be stored or transmitted and reconstructed later. This allows the data to be communicated between applications in a way both applications understand. Data serialization languages allow us to represent variables with text. **Variables** are containers that store values.
data serialization demo
### JSON **JSON** (JavaScript Object Notation) is an open standard file format and data interchange format that uses human-readable text to store and transmit data objects. REST APIs often use JSON. In JSON, whitespace is insignificant. JSON primitive data types: * **String** - a text value. It is surrounded by double quotes (`" "`). * **Number** - a numeric value. * **Boolean** - data type that has only two possible values (true or false). * **Null** - represents the intentional absence of any object value (`null`). JSON structured data types: * **Object** - an unordered list of key-value pairs (variables). Objects are surrounded by curly brackets (`{}`). The **key** is a string and the **value** is any valid JSON data type. The key and value are separated by a colon (`:`). If there are multiple key-value pairs, each pair is separated by a comma (`,`). Objects within objects are called **nested objects**.
object example
* **Array** - series of values separated by commas. The values don't have to be the same data type.
array example
### XML **XML** (Extensible Markup Language) was developed as a markup language but is now used as a general data serialization language. Markup languages are used to format text. XML is less human-readable than JSON. The whitespace is insignificant. Used by REST APIs.
XML example
### YAML **YAML** originally meant Yet Another Markup Language but to distinguish its purpose as a data-serialization language rather than a markup language, it was repurposed to YAML Aint Markup Language. It is used by the network automation tool Ansible. It is very human-readable. Whitespace is significant, indentation is very important. YAML files start with `---`. `-` is used to indicate a list. Keys and values are represented as `key:value`.
YAML example
{% file src="" %}