They're both taxable, it's the treatment for other tax items that's different. The difference between taxable and Capital Gains income is you don't have to pay self employment tax on Capital Gains. Also if you have long term Cap gains, you only pay 20% tax rather then the highest bracket % you fall into for short term cap gains. Also, you can only offset 3K of cap losses against taxable income. Where you can offset all your cap losses to the extent of cap gains plus 3K.
