The Magnetic moment is the total magnetic moment of a sample, in the CGS units it's measured in emu (equivalent in SI 10^-3 Am^2). While the magnetization is either per volume unit or per mass unit, emu/cm^3 or emu/g (10^3 A/m). 

The saturation magnetization (Ms) of Nickel is approx 480 emu/cm^3. If i measure 1 cm^3 of nickel at saturation the moment I measure will be 480 emu. if I measure 2 cm^3 the moment will be 960 emu. The saturation magnetization doesn't change, it's a material quantity. 

The magnetization is the number of moment by volume unit

The magnetic moment is associated with the spin and orbital motion of the electron. The net (vector sum) magnetic moment of electrons in an atom/ion gives rise to the magnetic moment of the atom/ion. Quantum effects and band structure plays an important role in determining the moment of an atom or ion in a solid. This moment is measured in units of emu (erg/Oe) in cgs system, and in A.m2 in SI system. The magnetic moment due to spin only of an electron is 1 Bohr Magneton = 9.27x10-21emu =9.27x10-24 A.m2. The orbital moment in most transition metals (except Co) is quenched, and the net moment is due to electron spin.  The magnetic moment of an Fe atom in metallic iron is 2.2 Bohr magnetons. To convert this into magnetization, which is the magnetic moment per gram (or magnetic moment per unit volume) we find the magnetic moment per cubic cell ( which contains 2 Fe atoms in bcc Fe metal) and divide this moment by the cell volume to obtain the magnetization in units of emu/cm3. The specific magnetization (emu/g) is obtained by dividing the above magnetization by the metal density. Fe example:

M = 2x2.2x9.27x10-21/(2.87x10-24)3 =  1725 emu/cm3

sigma = 1725/7.87 = 219 emu/g which is the specific magnetization for metallic Fe.

Fe3+ in iron oxide crystal has a moment of 5 Bohr magnetons at zero temperature (which is the sum of the moments of 5 electrons in the 3d-band) for example. The same procedure above can be used to calculate the magnetization of a collinear magnetic structure in an iron oxide or any other other magnetic material. 

The magnetic moment characterizes the magnetic properties of the body as a whole (extensive parameter). It depends on the magnetic moments of the particles that compose it, and their ordering, and the matter amount (amount of the magnetic material). In order to obtain material properties regardless of the sample size, the specific (intensive) characteristics used, namely moment per volume unit or per mass unit of the body. The magnetic moment per volume unit is called the magnetization M. In the Gaussian system of units the dimensions of magnetization, magnetic induction and magnetic field are the same, although they have different names (Gauss, G, Oersted, Oe):

B=H+4*pi*M, [H] = Oe = cm^(-1/2)*g^(1/2)*c^-1.

The magnetic moment per mass unit is called the specific magnetization, sigma: [sigma] = cm^(5/2)*g^(-1/2)*c^-1.

Thus, the electromagnetic unit of magnetic moment, emu has a dimension equal to cm^(5/2)*g^(1/2)*c^-1.

 In M(T) measurement,  suppose one have moment (let x emu) for a corresponding temperature, is it total moment of the sample or how will one convert this total moment  bohr magneton??? 

 To Binayak Sahu: 

In accordance with the answer of Prof. Sami Mahmood

Bohr Magneton = 9.27x10-21emu =9.27x10-24 A.m2. 

If the moment is divided by the mass of the sample you get specific magnetization in emu/g, and if divided by the sample volume you obtain magnetization in emu/cm3. The magnetization divided by the value of Bohr Magneton would give the magnetization in units of Bohr magneton/cm3 or Bohr magneton/g. In measurements involving variations of temperature it is preferred to use emu/g.

Themagnetisation M is a measure of the magnetic moment, m, per unit volume of material, but can also be expressed per unit mass, the specific magnetisation : 

 M = mtotal / V  

The saturation magnetisation (MS) is a measure of the maximum amount of field that can be generated by a material. It will depend on the strength of the dipole moments on the atoms that make up the material and how densely they are packed together.

The Magnetic moment is the total magnetic moment of a sample, and in the CGS units it's measured in emu, which is equivalent in SI 10^-3 Aּm^2 or 10^-3 joule per tesla   (J/T).  While the magnetization is either divided by volume  (in CGS- emu/cm^3) or mass of sample (in CGS- emu/gm). 

The difference is

Your Squid system measured your sample and give you the magnetic moment(emu).

If your sample is powder (gram) and you divided the magnetic moment (emu) by the sample wight (gram) you will get the Magnetization(emu/gram).

If your sample is thin films (cm3) and you divided the magnetic moment (emu) by the sample volum (cm3) you will get the Magnetization(emu/cm3).

If you would like to convert from thin films to powder or from powder to thin films you have to divided or mulitply by the Density (gram/cm3) of your material.

I hope this clear .. and help

Thank you so much Marzook Sir, it's very helpful information

If i have thin film and i want to find critical current density from magnetization curve width so i need to divide moment by it's volume get (emu/cm3) and then multiply by 10^-3 to convert it in to A/m so 1A/m= 10^-3*emu/cm3, and put it in Jc vs deltaM so i will get denstiy = A/cm2, Am i right?

Magnetic moment is sum of spin magnetic moment and orbital magnetic moment but magnetization is total magnetic moment.

Dear Ali Rafiei,

the sum of the spin magnetic moment and the orbital magnetic moment is total magnetic moment (this usually refers to atomic systems, such as individual electrons or atoms). The sum of the magnetic moments contained in a sample is the magnetic moment of a given body. And the magnetic moment of a unit of volume (also known as the volume density of the magnetic moment) is the magnetization M. The magnetic moment of a unit of body mass is usually called the specific magnetization s=M/r, where r is the density of the material (see the answers given in 2015). The word ‘magnetization’ is also used to describe the process of increasing the magnetic moment of a certain amount of matter.

Mudassar Nazir

Dear Mudassar Nazir,

It seems that your question and reasoning are from "a completely different Opera".