Mount Solder

what’s the difference thru hole soldering and Surface Mount soldering?
I am learning about microchips and detailed answers please.
In the through-hole soldering technology, the electronic components have a relatively long leads, enabling them to pass through holes in the printed circuit board (PCB), where they are to be soldered on the other side of the PCB.
In the surface-mount technology, the electronics components have short, normally flat leads because they will be directly soldered in the same side of the PCB that they are exist, i.e., with no need for holes in the PCB to fix the components.
Surface mount technology is a newer technology, it dramatically reduced the total size of electronic equipments, and that is its main goal.
You can find further information in the links below.
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