## General intro 
### XML :
Extensible Markup Language and related technologies.
Similar to HTML with some changes to better suit general data
Rich and expressive but more complex than JSON.
 
### JSON :
Javascript object notation.
Very concise format for serializing object data
Derived from JavaScript but supported by most modern languages
Compact and easy to read, write, and process.

## Specific info.
### XML :
Similar to structure to HTML but more strict.
Usually used for complex, document-like data.
Must always have a single root tag.
Can contain optional document declaraton
Empty tags must have a closing slash <tag/>
Attributes must have values that are enclosed in quotes.
Tags must be properly nested within each other.
Tags and attributes starting with "xml" are reserved.

### JSON :
Lightweight, text-based format for data interchange
Easy for humans to read and machines to use.
Derived from JavaScript, but language independent.
    - Number : Signed decimal number, no Integrer/Float distinction
    - String : Unicode or escaped characters inside double quotes.
    - Boolean : True or false value
    - Null : Null value
    - Array : List of ordered values
    - Object : Collection of key-value pairs, keys are strings

### Sending data to web services 
HTTP Operation  | Purpose

GET             | Retrive data from a web service

POST            | Create or update data on a web service

PUT             | Create or update specific data resource on a web service 

PATCH           | Perform a partial data update or edit on a web service

DELETE          | Delete data on a web service