No, at least not in the UK where there’s no copyright registration system. Copyright comes into existence automatically when a suitable work is created. Keeping records is therefore important in case it should ever be necessary to prove ownership of the copyright. It’s good practice to preserve the original work and to mark it with the copyright symbol ©, the date and the name of the copyright owner.
If you commission someone else, e.g. a photographer or a programmer, to create original works, the copyright does not automatically belong to you: it is important to get it assigned in writing.
As a copyright owner, you can stop other people from, for example, copying your work, making adaptations/translations of it or distributing or selling copies of it.
Copyright is infringed by a person who reproduces a “substantial part” of the work – simply making minor changes will not be sufficient to avoid infringement.
Copyright is also infringed by a person who knowingly imports, keeps or sells an infringing copy. However if it is possible to prove that a similar work has been created independently, without copying, there is no copyright infringement.
Copyright normally lasts until 70 years after the death of the creator of the work.