1x10E-6 is scientific notation for 1 micro-something .
1x10E-9 is scientific notation for 1 nano-something.
E means exponent - similalrly 10x10 = 1x10E2. 0.1x0.1 = .001, or 1x10E-2. A convenient way to show the portion of the number of interest without showing all the 0's.
When you multiply by 10, 100, 1000 you just move the decimal point around.
Move it to the right for 10, 100, 1000, E increases by 1 for each decimal place
56 = 5.6x10E1,
560 = 5.6x10E2,
5600 = 5.6x10E3
Move it to the left or 0.1, 0.01, 0.001. E decreases by 1 for each decimal place.
.56 = 5.6x10E-1
.056 = 5.6x10E-2
.0056 = 5.6x10E-3
so if you have 100 nano-somethings, that is written as 100.0 x10E-9
move the decimal point 2 place left to get rid of the 0s = 1.0 x10E-7
10E-7 is not in the list above, so move it one more place = 0.1x10E-6
thus 100nF is the more commonly seen 0.1uF.