We have several exterior security cameras covering strategic areas outside our house (we have been burgled in the past).
They are set up to alert us (on our mobiles, computers, tablets, if they are switched on) when they are triggered by 'human motion' during the day and all movement at night. They also take short recordings of anything that triggers them and we can also speak through them.
We set the areas we want to protect and also privacy zones so we cannot see anything our neighbours are doing.
The cameras need recharging from time to time (disable the anti-theft alarm before taking the camera down to recharge it).
The cameras rely on good WiFi signals and fast internet speeds.
We have had a couple of alerts at night when a spider crawled across a camera lens but mainly find them reliable.
Being able to speak to callers at the front door when you are miles away is very useful and you can see and record callers as well.
I have no experience of a camera inside a window though and the microphone would not work very well.