1x means the probe has no internal voltage divisor. 10x means the probe has an internal voltage divisor by 10. Usually probe has a small switch 1x/10x. For example you have maximum vertical scale 5V/div and 6 vertical divisions on the screen. That means you can measure voltage up to 5x6 = 30V. If you have a probe with internal divisor by 10 you can measure voltage up to 5x6x10 = 300V (with the internal divisor switched on).
How to make a Hi -frequency probe for low cost --
Take a 50 Ohm cable cut it and add a high value resistor (500K-1Meg) discrete component in series. This would be better than the commercially vailable probes.!!
(not the high end ones)
brmadhukar