doane_nut
The floor jack is much more stable so there is less chance of it tipping over at the wrong time. As you jack your car, it is going to move a little bit, tipsy bottle jacks are not good in this situation.

B M
Pro's - Floor Jack floor jack is more stable. safer easier to operate will roll on flat surface Con's - floor jack heavier, harder to pick up if needed takes up more room if you want to throw it in the trunk. I always suggest using the jack stands and floor jack when changing tires because the jack stands I have seen aren't the most stable either.

willywonker
Hydraulic jack is the kind of jack using a fluid to hydraulicaaly lift. Some are in the shape of a bottle (cheeper) that you would have to put under the axle to lift your car. The floor jack you can slide under from the side or back, making it a lot safer. There are several brands some of both are cheep for light duty use as yours.

Country Boy
A common hydraulic jack sits on a 4" x 6" square of steel. A hydraulic floor jack has three or four wide spread locations which distribute load much better and is much more stable. If you go to the following website there are a couple of very good aluminum lightweight floor jacks. I purchased the 910-82356 - 3,000 lb. three pump jack and found it to be rugged and very stable. The cost was$129.00 plus shipping. Any day now this site offers free shipping before the holidays. Our jack has been used in the garage and at the race track for a solid year with absolutely no problems. It'll lift to 17 1/2 in." and slide underanything 3 1/2" in. The side plates are thick cast aluminum so the frame will not twist as do the cheaper US General jacks do. Sears now has an all aluminum jack but I'm not sure of thhe price.