Difference between DC operating point and Transient operating point
SPICE transient analysis uses different analysis algorithms with different convergence-related issues and different initialization parameters than DC analysis. But, a transient analysis first performs a DC operating point analysis. 

Some circuits, such as oscillators or circuits with feedback, do not have stable operating point solutions. To simulate these circuits, the software either breaks the feedback loop so the DC operating point can be calculated or the initial conditions must be provided in the simulation input through .IC (initial conditions). The DC operating point analysis can be bypassed with various settings.

Once the bias is determined, the software  calculates the small signal circuit nodal voltages and currents, if these small signal values grow too large (or too far away from the initial DC operating point) the a new operating point is computed, a new set of small signal equations are computed around the new operating point and the process is repeated.

The series of operating points that are calculated are the transient operating points.

You can dump these and reuse them as initial conditions on the next run if you wish.