Dear student 
Electric Field Intensity vector
It is denoted as E
.Note here that, +1 C of charge is known as unit test charge .Electric Field is just the field. It is something spread out by the charged
 particle and its presence can be felt by another charged particles. Whereas field intensity is also the same thing.
Hope this helps.
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cheers
						

							Both of these terms are often used in place of each other. We do it quite nonchalantly. However, there exists a minute difference between these words. Electric field is used to describe a region of energy present around charges. A more thorough and quantitative definition is easily available on the net. There is no notation as such to represent electric field.

However, when we talk about electric field intensity, we are actually describing the vector aspect of an electric field. That is we are talking about the magnitude and the direction of it. Electric field intensity is usually denoted byE (With an arrow mark on the top).