You will find different USB and aux ports in almost all smartphones and often need to connect USB to Aux for our vehicles. The auxiliary ports are the ones that are often termed as aux or headphone jacks, the function of which is to deliver music sound from the phone to the earphones. Now, talking about the USB and aux ports in cars, the audio systems lag behind a little bit there. So you will most probably find a 3.5mm headphone jack or the aux and not a separate USB slot. Therefore, if you want to connect your phone to the car stereo you need to use the car USB to aux cable for that. Read: DIY Hacks To Create An Image Of USB Drive What happens on the USB to the aux cable? So when you connect the USB to aux cable in your car then you connect the mp3 player of your car to the computer/phone through which you can transmit information from one device to another. And as we know that the majority of the vehicles do not have a USB port pre-installed, for this reason, one has to use USB to aux cable when one has to listen to music or simply connect an mp3 player to the laptop or the phone. Also read: Headphone And Speaker Ports: Are They Different and How? What is the difference between USB and aux? One must be wondering about the differences between USB and aux and let us make it simpler for you to understand. So, when you use a USB cable it sends digital information and transfers data as you would do to a computer. Meanwhile, in aux cables aka headphones jack, the information is transferred as analog signals therefore it transmits audio from your phone or any device it is connected to your amplifier or your pair of headphones. To know which cord or cable to use for a particular port, you must know about the speaker system and the setup. Aux cables are useful in devices that have an old setup or have the setup only to receive analog signals and do not have a digital or USB interface. Aux is usually found in CD players, home theatre receivers, car stereo, etc. Related: Everything You Must Know About External DAC Coming on to the working of the USB cable, the USB cables transmit the data unprocessed, leaving it as it is without changing the format as in aux cables. But the universality of USB is not promised as we do not find them in every device as we find aux ports except for the latest versions of iPhone that have eliminated the headphone jack and introduced a USB port instead. Read: Why USB Drive Not Showing Up? 5 Common Reasons | Easy Fixes What is USB to aux cable and do they exist? Yes, USB to aux cables do exist and they serve the purpose they are made for, but if you plug a USB drive into the USB to aux cable, nothing will happen as it works on for USB ports. It is made to transmit audio signals from your USB connection. Now the question arrives whether we can plug a USB cable into the car USB to aux cable. Starting with the basic, when you store and save music files and data on your phone then it is stored as a digital file, and to convert those music files into audio format you need an app, program that would convert it into an analog signal that is transmitted to headphones, earphones or the speakers. Even though the USB aux cables do not form a universal port in all devices, they have many uses, especially in those devices that are made to receive input from the 3.5 TRS connection, you can also use a car USB to aux cable Also, you can use the USB to aux cable to connect your USB headphones to the 3.5mm headphone jack. But before you can do that, you have to cross-check once more whether your headphones do not require power over USB apart from receiving an audio signal. Only some headphones are made in such a way that they can work by converting the audio analog signal, but one cannot accept other headphones to accept digital information in the same way as these signals. Where can you use the USB to aux cable? The one place where you can make use of the perfect and the full use of USB to aux cable is while listening to music in the car that involves an mp3 player consisting of micro and mini USB without a headphone jack. All you need to do is to plug in the USB on your phone and aux cable in the car stereo and the USB to aux cable starts working as it should.