And that means what?
The ultimate goal for Mormons is exaltation in the Celestial Kingdom (highest of their 3 levels of heaven). This is celestial glory.
Mormons believe that they will continue to learn and progress there. It is also the only one of the three levels that has the presence of God the Father, the other 2 levels are lesser levels (non-mormons, less valiant or “active” LDS members go to these levels).
Part of this progression is to eventually become a God, with your own planet, and have “spirit children” who can then be born on that planet, live Mormonism, and gain exaltation.
Mormons also believe that this is exactly what our God did (and his God before him); that he was once a man, lived a life, was Mormon (even if it was called something else), went through the Mormon temple ceremonies, etc. in order to earn his Godhood.
The way it was explained to me when I was LDS was like this: We, as human parents, want our children to have a better life than we had, we cannot be BETTER than God, but we CAN be JUST LIKE HIM. God wants us to be the best we can and progress to Godhood. Furthermore, men and their priesthood are NEEDED to become Gods. A man (only men can have the priesthood) can become a God without a woman, but a woman cannot become a Goddess without a man.
One of the later prophets, Spencer W. Kimball said the following in a speech to the men of the LDS church:
“Brethren, 225,000 of you are here tonight. I suppose 225,000 of you may become gods.” (Ensign, Nov. 1975, p.80)
Hope this answers your question.