What the heck is colloidal silver?

I've heard hippie moms talk in online groups about colloidal silver, but never had experience with it. Once my holistic vet friend recommended I get some to put on my dog's wound, I knew I should learn more about this stuff.

It is literally silver particles suspended in a solution and is an ancient remedy. Colloidal silver is believed to help alleviate health conditions such as pink eye, eczema, sinus and ear infection and herpes. It may also help reduce your risk of cancer. It is a powerful kill-all for germs.

There is a lot of warning from doctors, even holistic doctors online, to not overuse and abuse this treatment, but to cautiously use it under the care of a medical provider. There are some risks and side effects with using it.