# 3. Intents and Manifest In the previous chapter, we learned about how XML and Java work together to constitute an activity. However if we want to create a full-fledged application, we'll need to build several activities, and we will need a way to switch between different activities and their corresponding screens. For our app to function in the Android operating system as expected, we would also need to understand how to manage our app’s status in the system. In this chapter, we’ll cover three important concepts that deal with these issues: lifecycle, intents, and permissions. ## Topics * Activities * Explicit Intents * Implicit Intents * Manifest * Permissions * Activity Lifecycle --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://android-course.cornellappdev.com/chapters/3.-intent-and-manifest.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.