AP mode allows a phone to connect directly to the ESP8266. The ESP8266 in AP mode forms it's own network, and a station device can then connect to it without a router.
I think (not sure) you are confused about AP mode because there are a lot of examples on the internet that have incorrect comments. And it seems that those incorrect comments are duplicated every time someone copies the code and modifies it for their own use. But still with the incorrect comment.
The router is an Access Point. When we connect to the router with our computers, phones, or ESP8266 they are Stations that are connecting to the Access Point (AP).
https://arduino-esp8266.readthedocs.io/ ... eadme.html
If i update that wifi manger page with some new text and upload it.
I don't know what you mean by wifi manger page. If there are pages that modify the SSID or password, then they are modifying the settings currently held by the ESP.
What I am saying is that you don't have to set the SSID and password every time the ESP starts up. It doesn't have to be in the sketch after an initial setup.
Load the example HellowServer sketch. Enter your SSID and password. Have it connect and confirm that you can access it. Then load a different sketch but comment out the WiFi.begin(ssid, password); line so there is nowhere that the ssid or password is in the program. Then when you start the sketch the ESP8266 will still connect because it had stored the ssid and password the last time WiFi.begin(ssid, password); was used. It retains that information.