USB:3.0:

Provides better speed. SS, 4.8 Gbps Allows better power efficiency with less power for

idle states. Can power more devices from one hub.2.0:High Speed or HS, 480 Mbps.

Polling(2.0), Asynchronous(3.0) mechanism.(Half duplex, Full duplex)Colour.

Why hard disk/RAM space not usable completely?

Wish of BIG DATA SCIENTISTS. As you know computer understands only 1's and 0's.

Also humans like rounded off numbers.(10 fingers, 10 toes)

Shown for us as 1GB=1000MB, but for computer 1GB=1024MB.

For every 1GB, we will be losing 70MB of data.

Processors:Intel Core is a brand name that Intel uses for microprocessors it releases.Core 2 quad/duo/solo/extreme lines.

What actually changes in these?

The numbers are simply indicative of their relative processing powers.Battery backup, power consumption, graphics improved, speed.I3: dual core, 3* rated.The more cores there are, the more tasks (known as threads) can be served at the same time.Turbo boost(dynamic over locking).

Recycle bin:

->Overwrite.->Disk defragmenter.->Delete files permanently.