regression in levels vs. difference

[mrrox]

Hi,

I am running regression on Eviews, I do not know the difference between running a model in levels and differences. Can anyone shed some light on this please?
Thank you!

[startz]

ls y c x
ls (y-y(-1)) c (x-x(-1))

[mrrox]

Thanks starts,

I am asking how I could interpret the results. I do not know when I should use differenced and level variables.