This quick tip is to help you out to determine what you are looking for. Note that in many places people use these two terms synonymously which can be confusing. If however when looking at a product it’s stated for one or the other the company usually knows what they are specifying.
Sound Absorption: With sound absorption you are looking to improve sound quality by removing noise that comes from within or close to the room. Sound likes to go everywhere you don’t want it to go especially while you want clear sound clarity.
Good example of this is while during a meeting you can hear people from the room next door or if while on a call there is complaints of hearing echos over the phone. Studio foam or acoustic panels are commonly used to help with sound absorption. Do note though they still can help while soundproofing a room but not as well as actual soundproofing material like drywall and foam.
Soundproofing: Usually meant for stopping noise coming in or out of an area. Here is where you wish to stop or reduce noise from traffic like roads or railways. At the same time something around you within your house maybe the cause of the noise like an HVAC system or type of loud machinery. Soundproofing with various materials can help block and isolate sound to make living within your home a lot more enjoyable.
There is soundproofing for pretty much everything like walls, doors, pipes, and windows. If looking to really invest in reducing noises coming from outside your house make sure to look at all various soundproofing methods to do everything you can to stop the noise.