When you ask How Is a CPL Different from a PPL the key point is this a Private Pilot License (PPL) is meant for personal non commercial flying for your own enjoyment or travel. On the other hand a Commercial Pilot License (CPL) is designed for professional flying where you can be paid to fly aircraft.
One of the major differences is in required flying hours and training depth. For example for a PPL you typically need about 40-60 flying hours while for a CPL you must complete a minimum of around 200 hours of flying. Also eligibility for a CPL tends to be stricter (higher age more schooling) compared to a PPL.
With a PPL, you can fly for pleasure take friends or family aboard (subject to rules) but you cannot fly for hire or reward. In contrast a CPL gives you the right to fly commercially carry passengers or cargo for payment act as a professional pilot join airlines or charter operations.
Because the CPL opens doors to professional flying careers (airline pilot corporate jet cargo pilot instructor) the training cost is significantly higher. For example a PPL might cost around INR10-20 lakh in India whereas a CPL could cost around INR45-55 lakh or more. If your goal is to fly as a profession and earn from it, then you'd opt for the CPL. If your goal is just to fly for personal passion or build basic skills, then a PPL will suffice.