What do the following electrical ratings mean on a digital timer?

I recently purchased a digital timer to connect my outdoor holiday lights. Reading the fine print on the back of the timer it says not to exceed electrical ratings. Here are the electrical ratings: 125VAC, 8A resistive 125VAC, 600 Tungsten I can find the voltage information for all of my holiday lights, but I do not how much voltage this timer can handle. Can anybody provide me with basic information as to how much voltage this timer can handle? I want to make sure I do not overload the timer. Correction: It should be 600W Tungsten.