A portable blender is a small appliance that can fit in a handbag, backpack or gym bag. They're cordless and you charge them with a micro USB or USB C. They're designed for blending on the go, whether you're in the gym on at work. Personal blenders are full sized, countertop blenders, but they're designed to only make a single portion of a drink. They typically make around 24-32oz which is only enough for one person, hence 'personal' blender.