I use an array of Foscam cams,inside & outside and they notify my phone with motion detectors. Some are wireless and some are direct wired. The pics on the phone are excellent, on the computer much better. Some save to a cloud, others on a SD card.
"Wireless" for the unsuspecting newbie buyer may be surprising, misleading, and confusing. Many assume they will need no wires at all. Most still require wired power to the cameras. Only the signal to the receiver is wireless. Other types are completely wireless and getting better all the time.
Do due diligence.
Figure out what your needs are. Do you want it monitored for example? Fire?
I have a Samsung Smart Hub and a few wireless sensors. I get notified on phone if there is motion or water and I can see current temp. They also have a camera you can get. It can also control lights and other products.
Ring.com sells products with a camera for door bell and floodlights.
Also look at SimpliSafe.