What is the difference between a phosphorescent source and a fluorescent source?

phosphorescent is glowing in the dark;reusing old light it has stored, like a glow in the dark keychain fluorescent is something that glows when energy is applied to it, such as the fluorescent lightbulb As the name implies, phosphorescent comes from the element phosphorus. Many other substances which are not phosphorus can fluoresce at certain wavelengths of light. I agree phosphorous like sea waves sometomes.