Online images are subject to the same laws as images in other formats: they may only be used, copied, altered, distributed (uploaded), or displayed (posted) with permission of the copyright holder, which is most often the creator.
There are millions of photographs and other images that have been given a Creative Commons license by their creators, which allows many uses without getting further permission.
Virtually all of them. The most notable exception would be images produced by employees of the federal government, such as NASA photos.
You can use others' protected material if you have an exemption in the law or a license from the copyright holder.
Copyright law.
Any designs or images you paint must be your own original work, based on public domain images, or properly licensed. But the original images you paint are automatically protected by copyright for the rest of your life and then some.
Oh yes they are. Disney holds the copyrights to all of their images, etc.
Public domain is the body of works no longer protected by copyright, which can be freely used by anyone for anything and it will not violate copyright law. However, some types of works include other rights such as trademarks or recognizable images of living individuals, which could be restricted under other laws.
The name cannot be protected by copyright, and has not been registered as a trademark, although common-law trademark would be respected as it has been used in commerce for some time. Images and other content supplied by Boss Chicks would be protected by copyright.
Books and other literary works are protected by copyright law.
The original works would be in the public domain, but books about them can be registered in such a way that the images and descriptions in the book are protected by contract law, if not copyright law. For example, a museum or archive holding a document can use contract law to limit exposure of images of that document, even if they can't use copyright law, which enables them to derive value from providing access to the original materials.
Copyright law is designed to ascribe exclusive rights to the creator of a work.
The copyright law of the country in which it was created would apply.
A website is considered a "literary work" under copyright law.
Technology would typically be protected by patent law, with the exception of software, which can fall under both copyright and patent.