What is the meaning for MateEntType=3 and MateEntType=4

"File = F:\\Files\\SWwork\\My Assembly.SLDASM"
"  Mates"
"    Coincident1"
""
"    Coincident1"
"      Type         = 0"
"      AlignFlag    = 1"
"      CanBeFlipped = False"
""
"      Component    = base-1"
"      MateEntType  = 3"
"      (x,y,z)      = (-5.59639294977956, -1.5868100626617, 0.484842721213511)"
"      (i,j,k)      = (0, 0, 1)"
"      Radius 1     = 0"
"      Radius 2     = 0"
""
"    Coincident1"
"      Type         = 0"
"      AlignFlag    = 1"
"      CanBeFlipped = False"
""
"      Component    = cylinder-1"
"      MateEntType  = 3"
"      (x,y,z)      = (-2.09639294977956, 0.663189937338302, 0.484842721213511)"
"      (i,j,k)      = (-3.49798081433316E-49, 6.16297582203915E-33, -1)"
"      Radius 1     = 0"
"      Radius 2     = 0"
""
"    ------------------------------------------------"
"    Concentric3"
""
"    Concentric3"
"      Type         = 1"
"      AlignFlag    = 1"
"      CanBeFlipped = False"
""
"      Component    = base-1"
"      MateEntType  = 4"
"      (x,y,z)      = (-1.84639294977956, -0.586810062661698, 0.109842721213511)"
"      (i,j,k)      = (0, 0, 1)"
"      Radius 1     = 6.49999999999999E-02"
"      Radius 2     = 0"
""
"    Concentric3"
"      Type         = 1"
"      AlignFlag    = 1"
"      CanBeFlipped = False"
""
"      Component    = cylinder-1"
"      MateEntType  = 4"
"      (x,y,z)      = (-1.84639294977956, -0.586810062661698, 0.984842721213511)"
"      (i,j,k)      = (-3.49798081433316E-49, 6.16297582203915E-33, -1)"
"      Radius 1     = 6.49999999999997E-02"
"      Radius 2     = 0"
""SolidworksApi macros