Ex 1

1. The main difference between ATX and BTX motherboards is the position of the slots.
BTX motherboards are like mirrored ATX boards. Where the connectors of the serial ports, parallel ports, keyboard, mouse, USB, etc. are soldered today we find the expansion slots in the BTX boards. And where the expansion slots are today, in BTX motherboards we find the board connectors (serial ports, parallel ports, keyboard, mouse, USB, etc.

2. The physical size does not affect performance. In fact, performance differences between motherboards (if all other hardware is the same) are not typical, perhaps a new memory controller may give a better benchmark score but that's about it.
Instead, look at the CPU socket and chipset, which determine amongst other things what processors you can use, also look at the type and number of expansion slots.
A Mini-ITX board supporting only single core Atom processors with 1 RAM slot and a PCI slot is not a basis for a high performance machine, however other ITX boards support other hardware.
The main advantage to ITX is its small size, leading to its use in small form factor machines such as HTPCs. ATX boards are more mainstream and due to the larger size generally have more expansion slots and therefore flexibility.
Is there anything specific you were wondering? The above is just general information which may not answer your specific question, if you have one.

3. ATX, or Advanced Technology Extended, and Micro ATX are the standard form factors for computer motherboards. The most evident difference is in size. Micro ATX motherboards are considerably smaller than regular ATX motherboards. Choosing one or the other can affect your future buying options--most notably, case compatibility.

Ex 2

CPU # 1. I7-3960X
Brand: Intel
Socket type: LGA 2011
Multicore number: 6
Frequency: 3.3 GHz
L2/l3 cache: 15 MB
Power consummation: 130 W

CPU # 2. Black Edition FX-8350
Brand: AMD
Socket type: Socket AM3+
Multicore number: 8
Frequency: 4 GHz
L2/l3 cache: L2 - 8 MB L3 - 8 MB
Power consummation: 125 W
CPU # 3. i5-5675C
Brand: Intel
Socket type: LGA 1150
Multicore number: 4
Frequency: 3.1 GHz
L2/l3 cache: 4 MB
Power consummation: 65 W
Why is cache important?
When computers were slower there was less of a difference in speed between the computer's memory transfer rate and the speed that the processor makes calculations. The processor can make calculations only as quickly as it can be fed data. If the processor doesn't have any data to calculate on a cycle, the cycle is missed and the calculation won't occur until the next cycle. The job of the processor cache is to eliminate as many wasted cycles as possible.
Why is important to know the power consumption of a peripheral component?
Each peripheral component draws a certain amount of power, so a PC technician may need to know how much power is needed for a component or many components on/in the computer. This would relate to making sure the Power supply has adequate output.

Ex 3

1. http://us.msi.com/product/mb/Z170A-GAMING-M5.html#hero-overview 2. Intel core i7-4790k is not compatible in MSI Z170A GAMING M5 because the socket is different.