# What is MSIX?

**MSIX** is a Window's #key# application package: allows users to integrate their application software on a hosting platform #key# format that provides a modern packaging experience while preserving the functionality of existing application packages. It also allows deployment on Win32, WPF, and Windows Forms App. 



## MSIX features

| **Feature**  | **Description**  |
| - | - |
| Reliability  |  MSIX provides a reliable install that boasts a 99.96% success rate over millions of installs with a guaranteed uninstall.  |
| Network bandwidth optimization  | MSIX decreases the impact on network bandwidth by downloading the 64k block only.  |
| Disk space optimizations  | There is no duplication of files across apps with MSIX, and Windows manages the shared files across apps. A clean uninstall is guaranteed even if the platform manages shared files across apps.  |

### MSIX Streamline

MSIX brings all the different *application packages*, old and new, on one streamlined format. It offers an interactive user interface or command line to convert and package Windows apps. 

### Breakdown of MSIX package

An MSIX package can be divided into two blocks: 
 * Package Payload contains Application Files. 

* Footprint Files contain AppManifest, AppBlockMap, AppSignature, and CodeIntegrity. 

## App Payload

**Payload files** are app code files and assets that are created when building an app. These payload files are needed to validate, deploy, manage, and update the app.

## AppManifest

The package manifest is an XML document that contains the information that the system needs to deploy, display, and update an MSIX app. This info includes package identity, package dependencies, required capabilities, visual elements, and extensibility points.

## AppBlockMap

The package block map file is an XML document that contains a list of the app’s files along with indexes and cryptographic hashes for each block of data that is stored in the package.

## AppSignature

The AppSignature is generated when the package is signed. All MSIX packages are required to be signed before install. With the `AppxBlockmap.xml`, the platform is able to install the package and get validated.


MSIX

MSIX is a Windows application package offering reliable installs, network and disk optimizations, and streamlined packaging for Win32, WPF, and Windows Forms apps.

Feature	Description
Reliability	MSIX provides a reliable install that boasts a 99.96% success rate over millions of installs with a guaranteed uninstall.
Network bandwidth optimization	MSIX decreases the impact on network bandwidth by downloading the 64k block only.
Disk space optimizations	There is no duplication of files across apps with MSIX, and Windows manages the shared files across apps. A clean uninstall is guaranteed even if the platform manages shared files across apps.