In the new donor card when you sign you agree to donate organs and tissues. The lifesaving organs are: Heart, lungs, kidneys, liver and pancreas.
Examples of tissue are corneal bone and skin. Although tissue is not a lifesaving organ and includes procedures other than organ donation, tissue donation can be of help to many people. For patients with a diseased or damaged cornea, a transplant could mean that these people could get their sight back.
The most important thing is that whatever you want to donate, the people closest to you know this and they can confirm this if/when asked.