A copyright is an intellectual property right in an original work of authorship. Each time you create something original — be it a photograph, a piece of writing or a video — you are simultaneously creating a copyrighted work.

“Original” means you created it yourself — it doesn’t mean that the work has to be ground-breaking. Ideas alone cannot be copyrighted, neither can facts. Example: You have written a 10-question quiz for students based on Shakespeare’s Romeo and Juliet. Guess what? You’ve just created a copyrighted work!

When you create a copyrighted work, you own a certain set of rights. These include the rights to copy, distribute, publicly perform, adapt (or make derivative works from), and license the work. You can exercise these rights by yourself and, more importantly, you can prevent other people from exercising them. You can also sell (the legal term is “assign”) your copyrights to another person.

More detail on the rights:

• Copy = Duplicate all or part of the work in some fashion. Example: Copying a PDF file to a CD.
• Distribute = Make copies of the work and make them available to the public in some way. Example: Selling the PDF file online or uploading the PDF file to Scoilnet so people can see it.
• Publicly perform = Exhibit or perform the work in a public setting. Example: Present and work through the PDF at a CPD event for teachers in a local education centre.
• Adapt = Make a copy of some part of the original work, but refashion or incorporate it in a new work. The resulting work is called a “derivative work.” Example: Modifying the PDF file to include comments/notes.
• Licence = Grant other people all or some of the above rights. Example: Allowing another teacher the right to use your PDF file or giving Scoilnet the right to distribute your PDF via Scoilnet.ie.

No. When you author a work, you create a copyright that you can use or sell. However, if you want to sue someone at a later point to prevent them from using your copyright without permission, it can be necessary to prove when you created the work. One way of doing this is to send a copy of the work to yourself by registered post (ensuring a clear date stamp on the envelope), retaining the original receipt of posting and leaving the envelope containing the copyright work unopened thus establishing that the work existed at that date and time.

No. Some people use the logo to let people know a work is copyrighted, but it’s not required.  

If you obtain permission (the legal term is a "licence") you can use another person’s copyrighted works as they’ve permitted. If their work had a Creative Commons licence attached, you do not need to obtain permission assuming you use it as they have specified.