what is culture appropriation?

something i keep seeing popping up from news articles to music videos, its culture appropriation:

i am unsure how such a beautiful thing, the coming together of different cultures is being seen as a negative. 

i understand someone being uneducated when it comes to ie.; wearing a bindi, but if its not done out of negative then surely its a good thing, i believe you should try to educate the person who may be misinformed, and then move on, not tell people they cannot do something because it belongs to someone else culture.

the harm that is being done is not someone wearing an indian head dress to a music festival dancing and enjoying themselves, it is the negativity being held onto, "you can do that because its only for weddings"

how about - "wow you look so lovely, we only wear that at weddings but you are more than welcome to embrace it and feel happy and beautiful"

The worst thing that will happen here will be:

"take off that 'am' necklace because you're not hindu, then the reply will be 'take off that pair of shoes that are made in portugal because you're not portuguese"... its a big leap but thats where it will end up.

there is beauty in sharing, there is beauty in education.

there is beauty in enlightenment.

just because that person is white or brown or yellow doesn't mean they aren't the same inside, can we stop being negative about anything thats a bit different and educate each other, share knowledge and stop claiming things for ourselves share things!

this is just my opinion and i do understand its not as simple as i have made it. but i believe in a  future where all religions are blurred, lifestyles are combined and we all actually get on and share stories.