This article will show you how to download iTunes on your Windows or Mac OS X computer. You can also install the iTunes Store app on your iPhone or iPad if you've uninstalled it (it's built into iOS). The iTunes desktop app and the iTunes Store app for iPhone and iPad are different programs with different functionality.
Method 1 of 2: On a computer
Step 1. Go to https://www.apple.com/en/itunes/download/ in your web browser
If you would like to receive notifications from Apple, enter your email address in the line on the left side of the window
Step 2. Click Download
It's a blue button in the middle of the window.
The site will automatically detect the operating system you are using. Otherwise, scroll down the page and click Download iTunes for Windows or Download iTunes for Mac
Step 3. Click Save
Step 4. Find the downloaded file on your computer
Step 5. Double click on the file
Step 6. Follow the instructions on the screen to install iTunes on your computer
Method 2 of 2: On iPhone / iPad
Step 1. Launch the App Store app
Click on the blue icon with a white letter "A".
This app is different from the iTunes Store app for iOS
Step 2. Click Search
This magnifying glass icon is at the bottom (iPhone) or top (iPad) of the screen.
Step 3. Enter itunes store in the search bar
It's at the top of the screen.
Step 4. Click iTunes Store in the search results
Step 5. Tap Download
It's to the right of the iTunes Store.
Step 6. Click Install
This button will appear instead of the Download button. The iTunes Store app is downloaded to your device, and its icon appears on the home screen.