To transfer data from an old Android phone to a new one, use Google's built-in transfer tools or third-party apps. The easiest method is to sign into your Google account during initial setup—Google automatically restores apps, contacts, calendar, photos (via Google Photos), and settings. For a more manual approach, connect both phones via a USB cable and use Android's File Transfer tool to move files, or use cloud services like Google Drive, Dropbox, or OneDrive to upload from the old phone and download on the new one. For specific data types: text messages can be backed up through Google Messages or apps like SMS Backup+; photos and videos sync through Google Photos; contacts sync with your Google account; and call logs can be backed up through Google Contacts. If your phones are the same manufacturer (Samsung, for example), check their proprietary transfer app—Samsung Smart Switch handles this seamlessly for Samsung devices. Bluetooth can transfer small amounts of data for music, documents, or photos. For encrypted backup of everything including app data, enable Android's native backup feature in Settings > System > Backup, ensuring it's linked to your Google account. Avoid relying solely on manual file transfer, as app data often doesn't migrate properly without using system backup tools. Test critical apps (banking, messaging, authentication) on the new phone to confirm everything transferred correctly before discarding your old device. Keep your old phone until you've confirmed all important data is accessible on the new one.