A frame of reference either at rest or having a uniform motion is an Intertial frame of reference. The external forces acting on a body in this frame are real or physical forces F. We use Newton’s second law in the form F = ma; to solve problems.
Any frame having an accelerated motion is a non-intertial frame. In such a frame, the body experiences:
(i) Physical force (F) and
(ii) Pseudo or Ficticious force, Ffie = m(-a*)
where a* is acceleration of frame of reference. To solve problem, in a non-inertial frame; using Newton’s second law, we have,
F + Ffic = ma
