From VASP Wiki

Information about convergence speed and about the current step is written to stdout and to the OSZICAR file. Always keep a copy of the OSZICAR file, it might give important information.

Typically you will get something similar to the following lines:

 reading files
 WARNING: wrap around errors must be expected
 entering main loop
      N     E                dE          d eps    ncg  rms     rms(c)
CG :  1   -.13238703E+04   -.132E+04   -.934E+02  56  .28E+02
CG :  2   -.13391360E+04   -.152E+02   -.982E+01  82  .54E+01
CG :  3   -.13397892E+04   -.653E+00   -.553E+00  72  .13E+01  .14E+00
CG :  4   -.13400939E+04   -.304E+00   -.287E+00  84  .48E+00  .39E-01
CG :  5   -.13401306E+04   -.366E-01   -.322E-01  69  .35E+00  .17E-01
CG :  6   -.13401489E+04   -.183E-01   -.169E-01  75  .74E-01  .66E-02
CG :  7   -.13401516E+04   -.267E-02   -.250E-02  68  .47E-01  .37E-02
CG :  8   -.13401522E+04   -.567E-03   -.489E-03  53  .15E-01  .90E-03
   1 F= -.13401522E+04 E0= -.13397340E+04  d E = -.13402E+04
 trial: gam=  .00000 g(F)=   .153E+01 g(S)=   .000E+00 ort =  .000E+00
 charge predicted from atoms
 charge from overlapping atoms
      N     E                dE          d eps    ncg   rms    rms(c)
CG :  1   -.13400357E+04   -.134E+04   -.926E+01   56   .97E+01

N is the number of electronic steps, E the current free energy, dE the change in the free energy from the last to the current step and d eps the change in the bandstructure energy. Furthermore ncg is the number of evaluations of the Hamiltonian acting on a wavefunction, rms is the norm of the residuum () of the trial wave functions (i.e. their approximate error) and rms(c) is the difference between input and output charge density.

The next line (after the N+1 lines) gives information about the total energy after obtaining convergence. The first values is the total free energy F (at this point the energy of the reference atom has been subtracted), E0 is the energy for (see also Partial occupancies) and dE is the change in the total energy between the current and the last step; for a static run dE is the entropy multiplied by . For a molecular dynamics calculation (IBRION=0) this line looks a little bit different:

   1 T= 1873.0 E= -.13382154E+04 F= -.13401522E+04 E0= -.13397340E+04 
    EK=   .19368E+01 SP=  .00E+00 SK=  .00E+00

T corresponds to the current temperature and E to the total free energy (including the kinetic energy of the ions and the energy of the Nosé thermostat). F and E0 are the same as above. EK is the kinetic energy, SP is the potential energy of the Nosé thermostat and SK the corresponding kinetic energy.

Additional technical parameters and some status reports are written to stdout.

The ouput to the OSZICAR file is also written for force-field only steps when machine learning force fields are used. In that case the E0 entry contains the same as the F entry since the entropy cannot be calculated in this method. The rest is analogous to the ab initio output.