There are many factors when we talk about residential smoke detectors and carbon monoxide detectors. We can talk brand, model, photoelectric, ionization, combination, dual, hardwired, interconnected, battery operated, battery back-up, plug-in, etc. Some of the determining factors needed to answer the questions you may have are: When was the house built? Has the house gone through any significant renovation? Any special electrical upgrade? If so, what year did the renovations take place? Is the house a single-family or multifamily?
Do you want to understand the different types of detectors? Are you looking for some more information regarding smoke and carbon monoxide detectors?
Reference chart for smoke detectors and carbon monoxide detectors:
More information regarding smoke and carbon monoxide detectors from the Department of Fire Services: