I have, at times written aps from scratch using VB.net, Java, C-sharp, i have created multi-threading aps to handle and address connectivity and capacity issues independently.
I am aware of what is part of an Application and what is not. I am not sure you do. based on what you are saying, it's not clear you do.
information you are accessing when off line is stored data at rest. At some level it is just a file of data that is retrieved and displayed.(that file is data, the file format it's on is an ap. Word is an ap, the information in your word doc is just data) That off line data is not an ap, that is data that an Ap can display. But that could be a word document, text document, or several others. That would use far less resources and memory to read.
you are using up memory in a very inefficient format that has to check for updates each time you log in. thus causing version and editing issues if not careful. (off line for a week, and your version could be outdated if something changed since) But that isn't an Application, it's data.
This site is full of data, the Application that it runs on is a forum template. This website is just a location, and has no data, the data is all in a database on the back-end. The forum software or application organizes and gives users the ability to do all we see and do, but behind the scenes it's all just code, a whole page to make the page look nice, and a simple query search to return the data that you have requested.
No internet, and no one would have the ability to go in a run the query unless they were plugged directly into the network hosting this site.
Apps for this kind of site, only act as a lazy mans book mark to go to the website. Since we don't download the forum software to remain on our computers or smart devices, and we don't constantly update those "stored" items either. Which are also a very serious concern for our saftey. As i am sure that no one would come here if they were getting malware or other nasty unknowns, which happens on all kinds of sites that force local data storage. (hence the longer and longer notices before you down load anything from the App stores)
This site is actually doing all of us a favor by not using up data on our devices, and storing data we don't need locally either.
oh and your link, that is a dummy guide that skips over the specifics and is actually not a very good description.. I wouldn't teach that to high school kids.
case in point.. "The app is a modern take on the word software or application. This is why you probably only hear it in reference to a mobile app or a small piece of software that's running on a website.
It's typically used to describe anything that isn't a full-fledged software program."
If an App, is short for Application or software, how exactly do they run some of the program and not the "full-fledged software" That isn't an option since you have to know that the code of a software program is compiled. You can't just run some of it without specialized software for programming. All the code is running and available, and while you may only be using or calling certain routines it's still running. If it needs to access a website, that is still just a routine and will get an error if you cannot connect. It's Like a retriever that is sitting at your feet eagerly waiting for you to say fetch. You just tell it what to fetch and it runs in a flow from routine to routine adding and compiling variables that are all pre-named and called as needed. give it something it can't do, and you should get an error, if done right.
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Have fun being an [beeep].. I hope it's all you hoped for.