Here we have a video that covers all the basics of redstone and logic gates needed to understand our Minecraft ALU
Included topics:
Redstone
Redstone Repeaters
Redstone Torches
NOT, NOR/OR, NAND/AND, XOR/NOR gates
Redstone
Redstone is the basic conductor of transmitting signals in Minecraft. It can be obtained naturally in the world by mining it deep underground. It possess just simple measures of conducting a signal across a distance. This however does have a caveat. The signal being passed along Redstone can only travel 16 blocks before it needs a "Redstone Repeater" to amplify the signal.
Redstone Repeater
Redstone Repeater is another component of redstone in Minecraft. It serves two basic functions; delay and signal amplification. When Redstone is passed through the Repeater, on the side with the moving torch in the GIF seen here, it can extend the signal to any redstone on the opposite side, where the stationary redstone torch is. It also has the potential to create delays. This is done by right clicking and moving the torch as seen in the GIF. At the start position, the two torches being the closest, it has a delay of 1 tick and can be increased up to 4 ticks.
Redstone Torch
The last main Redstone component that comprises the basic logic gates is the Redstone Torch. It is a source of power that is always on and transmits a signal through any adjacent redstone. It however can be inverted and turned off. This is done by placing the redstone torch on the side of a block and sending a powered signal of redstone into said block.