Unlike years ago there are many types of coolant in vehicles today.
Most of the newer cars on the road today have “lifetime” or “extended life” coolants, many of which are different from each other and are NOT compatible with each other. Older cars had a glycol type coolant (the green stuff) that would be changed every other year. Most of the newer fluids are designed to last up to 100,000 miles before needing any attention.
Because there are so many types of coolant, it is a good idea to check your owner’s manual for the maintenance schedule for your vehicle or just ask the technician when you have your car in for service.