If you are an average Samsung Galaxy S5 owner, i.e. without expert knowledge of the phone's hardware technicalities and software configuration, I suggest you learn how to boot your phone to Safe Mode and Recovery Mode . You may not be able to use them that often but, at least, you have a know-how in case your phone may encounter a problem that requires to use any of the methods cited here. This post will teach you step-by-step how to boot your phone to Safe Mode, Recovery Mode, wipe cache partition, and perform Factory Reset. I will also try my best to explain briefly the importance of these methods and when to use them. I divided this article into sections so it will be easy for you to find information relevant to what you're looking for. So, just click any of the links you can find after the break.