How do you connect your Android smartphone or tablet to your computer? Generally speaking, older Android devices support USB Mass Storage for transferring files to and from your computer. Modern Android devices use the MTP or PTP protocols. So that you can choose different USB connections according to your Android device.
Wifi: Transfer files by connecting Android to PC wirelessly
UMS: Connect Android to PC via USB Mass Storage
MTP: Connect Android to PC as MTP/PPT
Review: Review of MTP/PTP and USB Mass Storage connection modes
Connect Android to PC via USB Mass Storage (UMS)
USB Mass Storage (also known as USB mass storage device class) is the standard protocol used by flash drives, external hard drives, SD cards, and other USB storage devices to transfer files between the host computing device and the USB devices. It was an older way for Android users connecting Android device to a computer.
When you connect your Android phone or tablet to your computer, you’d have to specifically tap a “Connect storage to PC” button to make the Android device’s storage accessible to the computer over USB mass storage. When disconnecting it from the computer, you’d have to tap a “Turn off USB storage” button.
Connect Android to PC as MTP/PPT
MTP stands for “Media Transfer Protocol”. This kind of protocol is part of the “Windows Media” framework and thus closely related to Windows Media Player, allowing the transfer of music files on digital audio players and media files on portable media players, as well as personal information on personal digital assistants.
When Android uses this protocol, it appears to the computer as a “media device”. In practice, MTP functions a lot like USB mass storage. For example, an Android phone or tablet shows up in Windows Explorer so you can browse and transfer files. If you are a Mac user, you can use Google’s Android File Transfer (a simple MTP client) to transfer files back and forth on a Mac.
PTP stands for “Picture Transfer Protocol”. It was designed to be a standard protocol for communicating with digital cameras. When Android users this protocol, it appears to the computer as a digital camera. Any software program that supports grabbing photos from a digital camera will support grabbing photos from an Android phone when you select the PTP mode.
PTP works similarly to MTP. In this mode, your Android device will work with digital camera applications that support PTP but not MTP. Apple’s Mac OS X does support PTP, so you can use PTP mode to transfer photos from an Android phone or tablet to a Mac over a USB connection without any special software.
Review of MTP/PTP and USB Mass Storage connection modes
It’s true that connecting an Android phone or tablet via USB Mass Storage is convenient, but there was an issue with this method of accessing files. When the computer was reading files stored on the SD card, these files was unavailable to the Android device itself. System files was separated within two folders “/data” for system storage and “/sd card” for USB storage on the same memory support. Usually the installed apps and system files goes to “/data” and the user data along with too little space for downloaded apps. These partitions couldn’t be resized without interfering with the Android system itself (rooting the device). Therefore, modern Android devices use different USB connection protocols, MTP and PTP.
Many Android devices now use the Android Operating System Jellybean (4.x) or newer. These Android OS 4.x and newer have been updated to now support the MTP (Media Transfer Protocol) and PTP (Picture Transfer Protocol) connection type instead of USB Mass Storage Mode. In MTP mode, the Android device controls the input/output to the filesystem, so there is no risk of data loss because of cold disconnecting the device from USB. MTP allows you to use the SD card from both the Android phone and the computer at the same time, even to any desired number of them. With USB Mass Storage Mode, you only can do it from a device at a time, meaning that you have to unmount the SD card from the Android to view it on the computer, stopping apps, etc.