We give a review of different properties of dark matter halos .
Taken from different publications , we present results on ( 1 ) the mass and velocity functions , ( 2 ) density and velocity profiles , and ( 3 ) concentration of halos .
The results are not sensitive to parameters of cosmological models , but formally most of them were derived for popular flat \Lambda CDM model .
In the range of radii r = ( 0.005 - 1 ) \mbox { $r _ { vir } $ } the density profile for a quiet isolated halo is very accurately approximated by a fit suggested by Moore et al .
( 1997 ) : \rho \propto 1 / x ^ { 1.5 } ( 1 + x ^ { 1.5 } ) , where x = r / \mbox { $r _ { s } $ } and r _ { s } is a characteristic radius .
The fit suggested by Navarro et al .
( 1995 ) \rho \propto 1 / x ( 1 + x ) ^ { 2 } , also gives a very satisfactory approximation with relative errors of about 10 % for radii not smaller than 1 % of the virial radius .
The mass function of z = 0 halos with mass below \approx 10 ^ { 13 } \mbox { $h ^ { -1 } $M$ { } _ { \odot } $ } is approximated by a power law with slope \alpha = -1.85 .
The slope increases with the redshift .
The velocity function of halos with \mbox { $V _ { max } $ } < 500 km/s is also a power law with the slope \beta = -3.8 - 4 .
The power-law extends to halos at least down to 10 km/s .
It is also valid for halos inside larger virialized halos .
The concentration of halos depends on mass ( more massive halos are less concentrated ) and environment , with isolated halos being less concentrated than halos of the same mass inside clusters .
Halos have intrinsic scatter of concentration : at 1 \sigma level halos with the same mass have \Delta ( \log { c _ { vir } } ) = 0.18 or , equivalently , \Delta \mbox { $V _ { max } $ } / \mbox { $V _ { max } $ } = 0.12 .
Velocity anisotropyfor both subhalos and the dark matter is approximated by \beta ( r ) = 0.15 + 2 x / [ x ^ { 2 } +4 ] , where x is radius in units of the virial radius .