Everyone wants to be credited of his work. You feel disappointed when you know that someone else is making profit from your invention. The scientists will stop their researches if they are not sure of protecting their work. That's why many governments have made a copyright law, according to which nobody can steal your whole work or any part of it.
Copyright applies not only to scientific inventions but also to literary and artistic work. It includes like writing of novel, poetry, articles, music video, film, etc. copyright law demands the original form of work. In other words it should not be stolen or copied. The owner has exclusive right over his work. The owner keeps full right over his work throughout his life and no body can breach it even till 70 years after the death of owner.
There is a misconception among many people that it is obligatory to register your work if you don't want it to be copied. So these people should know the difference between registered copyright and non-registered copyright.
So you get protection of non-registered copyright as soon as you publish your original work. Of course this work should be in concrete form because ideas are not copyrighted. If you idea or script of film in your mind then you can't get it copyrighted.
If you get your work registered, then you make public known that you have created it. Moreover you can claim statutory damages if some one infringe in your creation. You should know that damages can be claimed even without registration. Registration also protects your design from international breach.
There is no such thing as international copyright which protects your work from international infringement. But, there are many countries who are member of Berne Convention and the Universal Copyright Convention which let you protect your creation throughout the word.
But there are some exceptions of copyright law which include fair use of material. For example if someone criticize your novel or article in newspapers, then he can excerpts some part or one specific paragraph or one line from your article and can publish in newspaper. It comes in the fair use because he has exclusive right to speak in against or favor of your novel.
There are some companies which help you registering your creation. If you do it yourself then it may be very time consuming. The company gets your work done so easy that you don't need to leave your home once.