We can see all sort of music and videos uploaded on YouTube.

I have two questions.

Question One:
If one creates the music or records a personal video, that would be fine to upload onto YouTube, I can understand that.

But I see all sorts of music and videos by various people around the world. For example, if I searched for a film, or music like 'Carpenters', Abba, etc. that has been uploaded not always by the creators, but by general public.

Wouldn't this be illegal? - for example to buy a film on DVD and upload it on YouTube?

Question two:
How does one know what is legal or illegal to download for personal use only, like viewing a movie offline or listening music offline?

I don't have the base for case of question..
The only thing is if we question to that platform would be better to address thier or better don't use such stuffs...
Rest for discussion it's ok..

You don't find a lot of good movies on YouTube due to copyright.
If you find movies there they're usually B movies and/or television movies and sound & vid quality tends to be not so great.

YouTube also removes a lot when they find it and there's a copyright issues.
If music is used in a movie the movie makers have paid for the rights to use that.
When you buy the DVD of the movie these rights are included in the price, for personal use, NOT commercial.

If you upload anything to YouTube or similar with someone else's music in it it'll be illegal as you haven't paid the commercial/public rights for the other's work.
That's why YouTube provides music to choose from that is copyright free. You can add this to your video without a problem.

YouTube also removes other things, not movie or music related. For instance when people upload part of a workshop.
If the uploader keeps doing it their channel could be removed but some find tricks around it. Still is a risk though.

Also, these days some vids from YouTube have a built-in code that is picked up by free YT downloaders so it won't download.
You can then listen to it on YT but not DL.

I don't think there's any country left that allows downloading for personal use.
In Europe we were the last country and it was stopped because the EU started whinging about it. So we're not allowed to DL anymore either.

As for the rest I think rules may vary per country as to what you pay and when for using for instance someone's music.
Over here companies & organisations that play music and/or radio have to pay for that. Cheapest solution is a year-license. Costs a couple hundred Euros but at least you won't get in trouble.
But it's why many smaller organisations & business owners do their thing in a fitness centre or such as then the centre has already got the license.

As for YouTube, I personally prefer not to use any music when I record one of my card-readings.
Because it remains a bit of a risk.

SparklingCrystal,

Thank You.

Extremely well explained.

I might decide to join and pay for YouTube premium membership, that way I can watch without adverts or download if there is the 'download' button, without getting into possible legal trouble.

You cannot avoid legal trouble paying for something if the person you are paying does not have the rights to sell it to you.

If there is a copyright issue with something being uploaded, you have to go to the copyright holder, not to anyone else, regardless of the claims they make.

In this case, I won't bother with any downloads. I will just buy any movies or music cd / dvd as I need them.
Many thanks for the further clarification.

I often see Americans (in reviews of a clip) talk about adverts and uploaders saying "ad free".
But I never get one single advert.
Install AdBlock, free extension on Google Chrome. No adverts anywhere anymore.
You don't need to pay for membership, get the free extension and you're good to go :)

As for downloading, personally I stopped downloading movies shortly after it became illegal here. Providers do not cooperate when film industry wants to investigate something, but if need be they can be forced by law to do so anyways.
I do stream though, then use a VPN.
My son told me FireFox has a VPN extension built-in that you can switch on.
I use an external one. Free btw, but good.
However, if your internet speed isn't fast you may notice as VPNs do pinch off speed.
I got 300 DL and 30 UP and I don't have a problem. But I did a speedtest once when running VPN and was shocked to find out how much it gets pinched off. So if your internet isn't very fast you may get buffering. Matter of testing it and finding a good VPN as that differs too.
Windscribe is good and you can get quite a lot of streaming for free if you also add your email and whatnot. Default is 5GB, but you can easily up it to 15GB by doing some thingies and still not pay a penny. And I find Windscribe is fast in its streaming, doesn't pinch off quite so much.
But you could get a paid for one too that does even less or no pinching off.

I do DL music occasionally. Not a ton and not all the time, but when I hear a song I want to have on my HD.
In essence no one is missing out money as I wouldn't buy the record anyway. I never did that really, not before internet was invented either.
But when I hear a good song in a movie or on the radio or something I do download it.

My kids told me the industry is far keener on catching people downloading games than movies/music.

I would say check the laws in your country or state if US to learn how strict they're dealing with downloading, and especially find out if they also take action a lot or not. Could be some countries are stricter than others.

Thanks SparklingCrystal for that further information.

I did buy NordVPN for two years.

With regards Firefox, which is good and I do use, check out 'Tor' browser. It give you security and VPN like no other. (https://www.torproject.org)

I do use Adblock+, I guess that is why I hardly ever see any adverts.

I have occasionally downloaded songs very few though. I normally just buy CDs.