The first option, "he has informed me" uses the present perfect tense. The second, "he informed me" uses the past simple.

You could use the present perfect for an action that happened in the past that has a result/relevance in the present. For example, "He has informed me of the instructions" (therefore I know what to do now).

The past simple could be used for an action in the past that has no result/relevance in the present. For example, "He informed me of the instructions" (but I didn't follow them).

M Shaf... You've asked a good question.

Ken and Joanne have provided good answers.

The two sentences say the same thing "someone informed you/you have been informed", however there is one small difference, i.e., the time of the action.

"He has informed me" tells us that information was provided to you at some point in the past and the time at which you were informed is not as important as the fact that you were informed.

"He informed me" tells us that information was provided to you at a specific point in the past and the time at which you were informed may be important (sometimes indicated by an adverb), e.g., He informed me yesterday/last week/two years ago, etc.

So, we would use the simple past if the time you were informed is important to know.

Otherwise, if the time of the action is not important, then either tense will suffice.

ken, Joanne, and Richard.. Thank you so much guys for taking time and explaining so much in detail. Much appreciated.. It got drilled into my head..

Very little difference between the two options you listed above. Both are considered ”past tense.”

The second example is more tightly written because you often don’t need the ”has”.

I wanna add in this group.