What these adhesives are for?

I'm actually very familiar with PCs and laptops, but I find this one pointless. Why did they stick these black and white glue exactly? I have never seen anything else.

These are thermal pads. You stick them on components if you want to compensate for height differences of a greater kind.

This serves in addition to electrical insulation, but also as mechanical protection for the circuit board during assembly.

The three black throws (is such a rubber) simply serve as spacers.

In any case, there are no thermal pads available.

Maybe the white is to hold on to the black foil. The black foil is used for isolation.

Maybe they missed, they don't have much time on the assembly line.

Not everything has a particularly deep reason. Sometimes you can find some hot glue or silicone somewhere that won't itch.

So the black things under the white band are thermal pads.

And as the name suggests, thermal pads are there to dissipate heat.

Is that absolutely necessary?

They already thought something. It shouldn't wobble and you want to increase stability with it.

In general, you can be sure that they will not shake hands too much if possible, because additional work costs additional money and in this business you can save 0.1 cents if you can.

I could imagine that this image comes from the inner workings of a laptop.

On the back (inside of the housing), e.g. Copper or aluminum foil could be glued as a heat sink (surface heat sink). These adhesive strips should electrically isolate the underlying (hidden) components (avoid short-circuit bridges) or prevent or minimize the reflection of heat from the heat-conducting foil (intended as a cooling body).

Just thought of it as an idea.