Beacon and Non-connectable advertising

Non-connectable Advertising, where a device transmits a string of data, but will not respond to any
request and cannot make a connection. This is the most common mode for beacons and can be
implemented using only a transmitter, with no receiver. the point that i am unable to get is how can the advertisement is sent to the central device( phones,tabs) with out making a connection and how can we tract the user data with out any connection? a string of data is the only thing that we send to the user and with out establishing a connection, tracking of user data possible in this scenario

The phone receives the RSSI (signal strength) of the beacon when ranging or determines an event upon entering a region (monitoring). To keep track of this data, you can send it from your phone to an online environment (for example an API) which saves it to a database. This means the following flow:

beacon --> phone < — > API --> database

Think about it this way: before you connect to WiFi, your computer first scans for all the WiFi networks nearby, and only when you click “connect” it’ll connect to one specific network. Or same goes for pairing with Bluetooth headphones: first, your computer scans for all Bluetooth peripherals, shows you a list, and then you click “pair”.

Beacons work pretty much the same way: your smartphone can scan for all beacons nearby without having to connect to them.

i will tell you my use case, when ever the beacon recognizes a device,it should send a push notification with out app.
i came to know that i can do that by the help of web services. How to do that ?
What is the connection between Web services and Beacon and how it will help me to push a notification to the user?