Quote from: Donald6680

Does the program work automatically if there is an internet connection or do I have to enter the program so that the program is active and does its work?

There's are options that can "kinda" set that behavior if you prefer it:

Go to your settings (Settings->Options...) then tick "Start Bitcoin Core on system login" under 'Main' tab. That will add Bitcoin Core to your start-up apps.
Then in the setting's 'Window' tab, tick "Minimize to the tray instead of the taskbar" so it can be hidden in your tray (the small icons and inside the arrow on the lower-right of W11 desktop),
You may also tick "Minimize on close" so you wont accidentally close it (you can use "File->Exit" to close Core).

Having intermittent internet connection isn't much an issue, your node will still run in the background (with those settings) but will obviously lose all connections while the internet isn't active.

Quote from: Donald6680 on July 29, 2024, 10:41:14 AM

What happens if, for example, I don't run the program for about 5 days?

When you start Core, it will show you the last block that it verified 5 days ago, start from that block to reach the current tip (latest block).
In other words, it'll download and verify those 5days worth or blocks.