SiteGUI platform is built on apps, each app is a collection of similar records, e.g: Page app contains all available pages, Product app contains all products and Blog app contains all blog posts. App can be a company internal application accepting inputs and allowing access from Site's staff only (e.g: Product app) or a customer facing app that also accepts inputs/access from Site's customers (e.g: Ticket app). App records can be made published to allow public/non-registered users to view and register for an account to add comment, like or vote.

SiteGUI App Builder is a low code web-based application that allows users to quickly create applications without writing any code. It is a great tool for developers who want to build powerful applications quickly and efficiently. App Builder uses a drag and drop interface to create fields, inputs, settings and automated actions for your application. It also let you customize the interface for editing or displaying records and add other applications as sub-apps to create relationship between this app's records with other apps' records. With the help of SiteGUI App Builder, you can easily build an instant application and deploy it to your site in no time!

Instant App is a type of app created by App Builder. It is built using all features and data offered by App Builder. Developers cannot run custom PHP code or SQL query, though the look and feel can be customized using templates. An instant app can be deployed to any site owned by the developer instantly without going through SiteGUI's app reviewing and approval process. An instant app can be made available to other sites by enlisting it in the SiteGUI's Appstore.

Remote App is similar to Instant App but uses remote API to process app records. This means you can connect your app to an API endpoint running on a different server and the API can be powered by any programming language. Remote App provides a flexible way to develop an app and let other companies to connect their Apps to the SiteGUI platform.

Standard App is similar to Instant App but it can run custom PHP code to process app records itself. As SiteGUI is a cloud platform, apps running custom PHP code will need to be reviewed and approved before it can be deployed to a Site or listed on the SiteGUI's Appstore. 

Core App is similar to Standard App but it can register custom routes and functions to provide custom actions for the app.

Widget app provides an interface to generate content such as carousel, slider, map (widgets) to be attached to a specified position on a page, product or other apps' record. The content may be generated using a PHP file or a remote API endpoint (Remote Widget).