|1) Not to the desktop. The ports you plug clients in to are 100 Mbps. The backplane is gigabit.|
2) You can buy a gbic fibre optic connector that plugs into the expansion module on the front of a 2950 to interconnect them with fibre. The gbic connectors are gigabit.
3) You could easily google each to find out what it means. In fact, I'm going to let you instead of telling you.