Is there a difference between 3D printing and additive manufacturing if any then explain?

I see several answers to that.

A lot of persons say 3d printing while they really mean additive manufacturing. For them, the machine got a 3d part out of raw material as a 2d printer got them images out of sheets.

Some persons think that 3d printing refers to lowpriced polymers additive manufacturing machines while additive manufacturing refers to industrial, expansive equipment like the so-called "DMLS"or "SLM".

Others persons say that additive manufacturing processes that use 2d-printers heads (ink injectors, such as HP additive manufacturing machines) should be called 3d printers and 3d printing because it's so similar to 2d printers.

I consider that "3d printer" should be avoided in general, because it is way too vague and referring to way too much different things. But it is up to anyone using these words, I just think that a serious person wouldn't use "3d printer" given all the mismatch that it could generate. I think we should use the exact process' name instead (like FDM for low-priced additive manufacturing polymer machines), or if you refer to the overall technology, use additive manufacturing.

Yes and No at the same time:

3D Printing is a subset of Additive Manufacturing

but treated as a synonym at this time

3D printing is a process that takes some material, in a fluid state that fuses with the model to shape an object from it. The material could be plastics, ceramic paste or even metal. The fluid state could be the normal state, or just be present for the fusing process (think powder and resin based systems), or be a transitional phase (as in filament based systems).

Additive manufacturing is just a slight bit bigger: at the moment most, if not all, AM processes are some sort of 3D printing. But AM could include other processes that don't fit 3D printing. For example, an automatic bricklaying machine could, under some view, be Additive Manufacturing, but it is not 3D printing in the traditional sense.

So: All 3D Printing is Additive Manufacturing, but not all Additive Manufacturing is necessarily 3D Printing.

Origin

3D printing and additive manufacturing (AM) both refer to a range of processes where, opposed to subtractive manufacturing methodologies, materials are joined to create products. E.g. FFF, SLS, etc.

From this reference you see a reference to 3D printing:

Additive manufacturing is the official industry standard term (ASTM
F2792) for all applications of the technology. It is defined as the
process of joining materials to make objects from 3D model data,
usually layer upon layer, as opposed to subtractive manufacturing
methodologies.

From e.g. this reference one reads that there is no difference:

Between the terms 3D printing and additive manufacturing, there is no
difference. 3D printing and additive manufacturing are synonyms for
the same process.

Useage now

However, as the AM processes and applications grew in time, 3D printing has become a subset of AM. As worded by Peter Zelinski in August 2017:

To be sure, the terms overlap. They can be used in ways that make them
sound like synonyms. But the relationship between them and the
difference between them is this: 3D printing is the operation at the
heart of additive manufacturing, just as “turning” or “molding” might
be the operation at the heart of a conventional manufacturing process.
In short, additive manufacturing requires and includes 3D printing,
but it also entails more than 3D printing, and it refers to something
more rigorous.