I read in another thread that they push the housing so that cable gets actuated?

I understand the general idea behind that, but i can't visualize what actually happens...

can anyone help me out? paint the picture a little more clearly for me?

Thanks in advance...

while i'm asking things...

can anyone explain to me how this works?

https://sheldonbrown.org/px7.html

about halfway down the page, the part about "dual control front brakes"

ttt

To install the inline brake levers you split the cable housing at the spot where the levers are to be installed. The brake cable runs through the levers with the housing on each side of the lever. When you use press the inline brake lever, the split brake cable housing is spread apart. Spreading apart the cable housing tightens the brake cable and causes the brakes to apply.

Its similar to what happens when you tighten your brakes with the brake caliper adjuster. Your basically increasing the cable housing length when applying the inline brakes. A longer housing with the same length cable tightens/applies the brakes.