I missed this one when it was first posted. But I can help the next person with the same questions
Indeed : ) There's nothing like a picture, or in this case examples, for making things clear.
What actually happens when I sync with eg Facebook?
I'm not a Facebook user, but I think I can tackle this one. Facebook sync is for your contacts. If I know you in real life and you have me in your contacts, and I also have a Facebook account my Facebook contact information will be added to your address book. For example:
We're friends. All you need for me in your contacts is a name and a phone number. We're also friends on facebook. On Facebook I have entered all my other details like address and birthday and a second phone number. When you sync your contacts, that gets transferred to your phone and merged in your address book.
It also needs to be said that Facebook sync on Android really sucks. How it is supposed to work and how it actually works can be two very different things and there are plenty of horror stories about your contacts being duplicated (sometimes over and over). It's my advise to not do it, and if there's something on my Facebook profile you need to have in my contact card you should enter it manually.
Is it true to say that if I have auto-sync on for a certain application, say GMail, then the GMails on the phone and on the computer will always look the same? New mails will appear in both, a mail that's deleted in either will be deleted in both, one marked as read or unread in either will be marked as such in both? Etc?
If you have autosync enabled for Gmail on your phone, anything you do in the Gmail app also happens in the cloud. It you delete a mail message it is deleted on the server. If you send a mail or archive a mail or save a draft or anything else, it is also done in your gmail account online.
Does it depend on having the same email client on both?
And having the computer on all the time? Or, when I turn it on, will everything have magically changed to the same as the phone?
If you go to the gmail website it will be exactly that same as the app on your phone if you have autosync enabled in the app. You can open the gmail website and do something on your phone and watch it change on the website a few seconds later.
The same thing will happen if you use a mail client on your computer and it is set to autosync. Depending on the client, it may need to wait until its next sync cycle (many desktop mail clients automatically sync, but at a defined interval instead of always and instant)
I have Outlook on the computer and use Gmail (because I don't know any better : ) on my phone, non-synced. So I can delete non-urgent emails from my phone, so as not to clutter it up, safe in the knowledge that they will still be there on the computer. I find that useful.
For some reason it doesn't work the other way: whatever I delete on the computer gets deleted on the phone too...
Outlook has a setting that deletes mail on the server when you delete it from your mail box. Since it's not on the server, when you open the gmail app and it refreshes and syncs (that happens every time you open it) it no longer sees the message because it's no longer there.
If you want to stop it from doing this, change the setting for that account in the Outlook program. Even better, make a folder and name it something so you know it has stuff you deleted from the computer side. That's not trash, so that folder will appear on the phone. You'll eventually run out of space in your gmail account, but I just checked and i have 49,022 email messages archived and in my account. You'll be good for a long time.
And lastly... Where does The Cloud come into it?
Thank-you,
Part of the cloud is where any changes are actually done. Since we're talking about Gmail, let's use it as an example.
You read an email from john doe on the gmail app on your phone. When you're done, you delete the message.
What you are doing is telling the cloud to delete your message. Your space in the cloud is isolated from everyone and everything, even you. But the computers that have your account details on them can also take any of your requests and do what you have asked. In this case, they will know you read an email (and mark it as read a few seconds after you have opened it) and then you deleted it. They will move the message from your inbox to the trash folder. When it comes to your account, the cloud computers will only accept a command from you. We all have our own place in the cloud and it works the same for all of us.
When you are home and you open your Outlook program, it syncronizes with the cloud — not your phone. The cloud tells Outlook what messages are there and what messages are deleted, and Outlook listens and does the same on it's end for any messages that have been downloaded.
If you checked your mail on Outlook but did not read that email from John doe, a portion of that email (called the header) was downloaded to your computer. The cloud is what can remember what you did on your phone and tell outlook to do the same thing.
The cloud is also storage space for your stuff. Since you have a Google account, you also have a Google Drive account ready to activate if you haven't already activated it. part of that Drive account is free or paid online storage. You can store anything you want (except a file with a virus as drive scans when you upload and when you download) in your drive storage, until you reach the limit and have no more space.
Other companies like Dropbox, SpiderOak and Microsoft (there are quite a few) also offer free cloud storage and have apps in Google Play you can use to upload and download your stuff to them.
Both ways you use the cloud — as storage for your stuff and account data for all of your Google apps -— are the same from every device you use to access them and changes are almost instant. This is how apps like gmail know what you did on one device and make another device match that as well as upload something from one place and download it form another.