Are android apps still running in background if I am getting notifications?

Question

Here is the thing, I am not used to the latest android yet and the new system is giving me some confusions. Usually, for the older androids, if I close all background apps, I won't get new notifications from them. But after switching to a new phone with the latest android, I realized that even if I do close all background apps, I still keep getting notifications from them. So, how are the apps still pushing notifications if I already close them from background? (Say google maps for example, I am 100% sure I killed it in background but now it keeps notifies me about my live traffic status on my notification bar.)

Answer 1

So Here's the answer-

Yes, they are. Whenever the Internet is turned on or you get a message, listener of that app wakes up and check for any notification and if there is something new, it shows you the notification.
These apps keep running in the background if not put in sleep mode by your phone and use the resources.
Like you don't want to get notified by WhatsApp for a new message but the moment you change the network, unlock your phone again or turn the data on, an event listener will wake up and notify you of new messages.
Also, wake timers are used to notify you after some fixed time like after every 5 minutes.
This is the thing I hate the most.
Not promoting but here's the app - search play store for Shutapp - Real battery saver. It will turn off all the background apps and you'll be amazed to see a long list on first use.
This will remove all the apps from background until you open them again. I use this app most of the time and it really works great.
Try this out.