What are Intents in Android?

Question

Accepted Answer

**Intents** are messaging objects used to request an action from a component — most commonly to **start activities** (navigate between screens), but also to start services, send broadcasts, and communicate between apps. They're fundamental to how Android components interact.

## What Intents do

```text
An INTENT is a message describing an operation to perform:
  → START an ACTIVITY (open another screen, in your app or another app)
  → START a SERVICE (begin background work)
  → DELIVER a BROADCAST (system/app-wide event)
  → carry DATA (extras) and specify the target/action
→ The mechanism for components to request actions and communicate.
```

## Explicit vs implicit intents

```kotlin
// EXPLICIT — specify the exact component (e.g. navigate to YOUR another activity)
val intent = Intent(this, DetailActivity::class.java)
intent.putExtra("itemId", 42)        // pass data
startActivity(intent)                // open the activity

// IMPLICIT — specify an ACTION; the system finds an app that can handle it
val intent = Intent(Intent.ACTION_VIEW, Uri.parse("https://example.com"))
startActivity(intent)                // opens a browser (any app that handles ACTION_VIEW)
// other examples: dial a number, share content, open the camera, send an email
```

```text
EXPLICIT → name the exact target component (used WITHIN your app, e.g. navigation)
IMPLICIT → describe an ACTION; the system picks a capable app (interact with OTHER apps:
  open a URL, share, take a photo, etc.)
```

## Passing data and getting results

```text
→ EXTRAS — attach data to an intent (putExtra) → read it in the target
→ Get a RESULT back (Activity Result API) — e.g. pick an image and receive it
→ Intent FILTERS (in the manifest) declare what implicit intents your app can handle
```

## Why it matters

Understanding Intents is fundamental to Android development because they're **how components interact** — especially how you navigate between screens — so it's must-know foundational knowledge.

An **Intent** is a messaging object that requests an action, and its most common use, **starting activities to navigate between screens** (passing data via extras), is essential to virtually every Android app (moving between screens is core functionality).

Understanding the **explicit vs implicit** distinction is key: **explicit intents** (naming the exact target component) are used for navigation within your own app, while **implicit intents** (describing an action that the system matches to a capable app) enable powerful **inter-app interactions** — opening a URL in a browser, sharing content, taking a photo with the camera, dialing a number, sending an email — letting your app leverage other apps' capabilities, a distinctive and powerful Android feature.

Understanding **passing data** (extras attached to intents and read by the target) and **getting results** (the Activity Result API for receiving data back, like a picked image) is necessary for components to communicate and exchange data.

Understanding **intent filters** (declaring what implicit intents your app can handle, so other apps can invoke yours) completes the picture of inter-component and inter-app communication.

Since Intents are the fundamental mechanism for Android component interaction (especially navigation between screens, a core need, and inter-app communication, a powerful capability) and understanding them — explicit vs implicit, passing data, and getting results — is essential for building apps that navigate and interact, understanding Intents is essential, foundational Android knowledge — a core concept for how Android components and apps communicate, necessary for navigation (used in every app) and for leveraging the Android ecosystem's inter-app capabilities.