The transparent latch acts as a D-FlipFlop. This is an important method of storing data. The left side is the data input, whilst the back is the clock line. This means that when the back is powered, the two outputs, which are the front and left by default, will hold the value of the data input, default left. The output will remain the same untill the clock input rises again, at which point the output will again relfect the data input. This is a method of storing a bit of memory.