I think alot of folks get confused about these two.

The Service Engine light comes on after 7500 miles, or after 750hrs of driving, or after 12 months, whichever comes first.

The Check Engine light, also called the Malfuntion Indicator Lamp(MIL), is the more serious of the two. It comes on if the cars computer (engine diagnostic system) likely has a "code" that needs to be read. Go to a AutoZone or dealer and get have it read. AutoZone does it free.

I think alot of volvo drivers see the Service engine light come on and pull over, get scared, and its not necessary,....if people knew the difference between the Service light and the Check Engine light they'd be better off.

Feel free to give me feedback or comments about this issue.

Many cars besides Volvo have had both for many years now AND all that is discussed in any cars OWNERS MANUAL.
As for free code reading, realize that that's not free diagnosis. A code doesn't always mean "bad part" and Autozone is trying to sell parts by doing that, assuming that they'd even have the correct part for a Volvo.

Regarding Autozone reading your codes - it's true that they have an "ulterior motive" for providing this service. But, it's still a valuable service for those who don't have their own OBD2 code reader, and you're under no obligation to buy any parts from them following their code scan.

Even if your not a DIY person and the codes mean nothing to you, it's not a bad idea to have them read at Autozone before bringing it to the dealer.

" it's not a bad idea to have them read at Autozone before bringing it to the dealer."

Being a dealer tech, I can tell you that IF you're planning to go there anyway, there's no need to waste time stopping at a parts store first. No dealer tech (or tech anywhere) will go by another places fault codes for diagnostic purposes. Any tech will read their own fault codes first and Volvos fault codes aren't the same as a generic scan tool.

If one goes to Autozone, gets a code read, buys that part and gets lucky, fine but it doesn't always go that smoothly and one might also waste money if it's not that part.