Brother Abd_mumin you should know Salafiya is following our beloved prophet alejhi selam, the sahabas and our rightous predecesors. Salafiya is an abriviation of Salafu Salih (rightous predecessors. So Salafiya means following the rioughtous predecessors. The salafiya are the ehli sunnah wel Jemmah.
For more information about Selafiya there is a topic at the category of religion.
In the name of Allah, the Beneficent, the Merciful.
I will explain. Muslims are divided in so many sects nowadays that people dont know which is which. before long ago there were really only muslims. Now there are Shia's, ahmadiya's, selefiya's etc..
to make a distinction. The real muslims call themselfs sunni which means: we follow the sunna(example) of the prophet Muhammad(peace be upon him). The only ones who follow this are the so called Ahle sunna wal Jemaah(=the group of people folling the sunna)
there are 4 schools of mazhabs who follow true guidence these are: Hanefi Mazhab,Safi,Maliki and Hanbali
when a person becomes muslim he/she chooses one of the 4 and stick to the rules offered by the mazhab.
from my limited understanding, in general, muslims are people who practice islam and a "sunni muslim" is a muslim person who's in a part of the world where there's too much sun - like singapore! hah!