Hey guys whats the difference between a SMPS and PSU … both look the same … i was suggested to upgrade my PSU cause i was buying a new graphic card … searched in google but they look almost same … if i insert a PSU means i have not to go for SMPS … does they both fit in the same place or what seriously confused please let me know … Sorry for a DUmb Question ..
PSU is one type of SMPS
Mainly four types of SMPS : AC → AC, DC → DC, AC → DC and DC → AC
As you know … PSU is AC → DC 
SMPS is a PSU. SMPS stands for switched mode power supply and PSU stands for power supply unit.
It is refered with both names.
Both SMPS and PSU are generic terms that refer to a unit that supplies power to a load possibly after conversion from a source type to the type required by the load. The source and output types can be any type and voltage, but in PC terms, they refer to a unit which steps down the AC current from the wall outlet to DC current of appropriate voltages required by the PC components.
Look, let’s not confuse him more here. An SMPS is a type of Power Supply, i.e. Power supply unit.
Practically ,what he’s asking for is “What do I ask for when shopping for a power supply for my PC?” (I hope that’s what you’re getting at). If so, then you can ask for either, you’ll get what you need. They both slot into your PC and power the entire rig. Just ask for a higher rated Power supply than the one you have.
Yeah dats nice and simple … atlast i understood thankx every1 4 replying and sorry 4 this dumb question 