If you are a regular W-2 employee, you pay only GA tax, unless you actually physically work in another state, see http://money.cnn.com/2013/06/28/pf/taxes/business-traveler-tax-threat/
If you are a contract worker, and will receive a form 1099-NEC, CA will tax you on that "self employment" income since your "Client" (employer) is located in CA. You will also report the "CA income" on your GA return, but GA will give you a credit, or partial credit, for the tax you pay to CA. Reference: https://www.coblentzlaw.com/california-office-of-tax-appeals-gives-precedential-authority-to-bindley...
