what are the physical significance of electric field??
A field in physics means a physical object that has a finite value everywhere in a given region of the space.
Electric field is a space around a charged object where the influence of the charge can be felt. Now as a charge can experience force due to another charge, thus the influence here becomes the force, so electric field is called a force field too. Mathematically, in this case electric field intensity which is force experienced by a test charge placed at that point of the field, gives the estimate of the strength of the field at that point.
electric field tells about the force acting on a unit positive test charge due to the other charges.
It also states that the charge q accelerates due to the colombic force between the charge and the test charge and produces electromagnetic wave, which propogates in a medium with a speed equal to the speed of light. This wave or charge when reaches the test charge it produces a force on it.
there is no existence of electric field or electric field lines, but this is an important and effetive way to deal with multiple charges. conceptually it is a refion ehere a perticular charge suffers a electric force. for different test charges the electric fieled is same if they are at the same distance from the source charge