The term "i9505 cf-auto-root" refers to a process related to rooting the Samsung Galaxy S4, which has the model number i9505. "Rooting" is the process of gaining privileged control over the Android operating system on a smartphone or tablet, allowing users to install custom ROMs, modify system files, and perform other actions that are not permitted by the manufacturer.

Here's a breakdown of the terms:

• i9505: This is the model number for the Samsung Galaxy S4.
• cf-auto-root: This is a tool or script that automates the process of rooting the device. "CF" typically stands for "Chainfire," which is the developer of the CF-Auto-Root tool.

The process of using CF-Auto-Root on the i9505 involves the following steps:

1. Backup: Before attempting to root your device, it's important to back up all your data to prevent data loss.
2. Download: Obtain the CF-Auto-Root file for the i9505 from a trusted source. Make sure to download the correct version for your specific firmware.
3. Bootloader Unlock: Unlock the bootloader of your Samsung Galaxy S4. This is a prerequisite step for rooting and can void your warranty.
4. Odin: Install Odin, which is Samsung's flashing tool, on your computer.
5. Flashing: Use Odin to flash the CF-Auto-Root file to your device. This will install the necessary root files and automatically root your device.
6. Reboot: After the flashing process is complete, your device will reboot, and you should see a SuperSU app in your app drawer, indicating that the device is rooted.

Please note that rooting your device can void your warranty and potentially brick your device if not done correctly. It's important to proceed with caution and only if you are comfortable with the risks involved. Additionally, keep in mind that the process may vary slightly depending on the firmware version of your Samsung Galaxy S4.