[SOLVED] Why do motherboards have sockets for soldering the SMD components?

[Jacob 51]

I was just chilling and I noticed that my motherboard has some slots for SMD ICs to solder on them. Whats the use of those slots? Is it used by the manufacturer?
Is it for fixing the motherboard?

 

[kerberos_20]

its not for fixing, its there for features available for your board version, if you see some "missing" parts, then it means that either those chips arent needed or there is more pricey version of your board