A common question posed to photographers is "do you Photoshop your images?" The fact that "Photoshop" is a product name and not a verb aside, let's discuss what people really mean when they ask the question and what it means to "Photoshop" something.
What's really being asked is, "do you manipulate the photo captured by the camera after the photo is taken". This is already beginning with an assumption that manipulation of a photograph begins after the time of capturing a scene in the camera, but that isn't true. Manipulation of what will determine the final photograph begin right from the start of the photographer visualizing the image they want to create.
Editing images encompasses a huge variety of possible changes to an image, before, during, and after capture, some are minor and some extreme. Examples of minor alterations include deciding where to stand while taking the picture, kneeling, climbing a ladder, holding the camera horizontally or vertically, adjusting the brightness, contrast, sharpness, and perhaps color temperature. More moderate alterations might include cropping the image, removing or diminishing the prominence of objects such as acne, scratches, tattoos, and small adjustments to the body like brightening teeth and eyes, fixing pinched looking skin or clothes, fly away hairs, trash, graffiti, or power-lines. Major alterations might include making changes to parts of the body such as making someone appear dramatically thinner or heavier, replacing or combining parts of the body with someone else's, completely changing the background, or adding things into the image that weren't originally there.
One of the problems when confronting this issue is that how much a photograph is altered will depend greatly on the purpose of the photograph. Many people tend to think of any photograph created using a camera as the same thing, that is they don't distinguish the tool (the camera) from the intent of the the person creating the photograph.
How much alteration, and whether that alteration is appropriate, will also vary depending on the photograph's purpose, such as something created by a photojournalist versus a fashion photographer creating an image designed to sell clothing, versus something to be sold purely as art. Most people would agree that a photograph for a news story should be altered as little as possible but what about for other sources? Some people think it is somehow "cheating" to alter a photograph because it isn't real but I believe the more you understand photography the more you'll understand a photograph is never real and is always a manipulation or an interpretation of reality.
To understand manipulation in photography it's important to understand what photography really is and how a photograph is created. The more you understand the history of photography, how cameras work, and how photographs are created from an artistic point of view, the more obvious it becomes that a photograph is never a true representation of "reality" and that a photograph, any photograph, is a manipulation. This is because photographs are created by combining human thought and a camera, and cameras don't work the way the human mind/eye combination works. They are created through the entire process of mental visualization, scene setup, moment, capture, and processing. This is the same with modern digital cameras as it was with the film cameras being used a hundred years ago. The only difference being that with digital cameras the capture is created on a digital sensor and saved to an electronic device and then processed using a computer and software while with with film cameras the capture is made to film and processed using chemicals and hardware. Photographs, in fact, are much closer to being painting than they are a representation of reality. Like a painting, they can be made to appear more or less realistic.
Most people don't realize the extent to which images captured on film are manipulated before they become the final photograph, and not just manipulations falling under the "minor alterations" category I mentioned earlier. Many historical photographs had major alterations applied to them, including combining parts of different images to form a completely new one. Even an iconic image of President Abraham Lincoln was very likely "photoshopped". See the fascinating story on that at Atlas Obscura.
Manipulating the image captured inside the camera has been a function of creating the final photograph for as long as there has been photography. In fact, from the moment a photographer visualizes their image they are manipulating the photograph. This is true for even the most unaltered images because the simple act of choosing where to stand and what to frame in the photograph is already manipulating the scene.
Imagine a scene laid out before a photographer. If we were standing there we could turn our head and look in different directions: left, right, up, down. We could talk to the people around us, hear the sounds around us. Now imagine a photographer is standing right next to you and they have just taken a photo. In order to have taken that photo they had to select and attach a lens to their camera, adjust their camera's setting controlling how much light to let into the camera and for how long to do so. They would make a decision of where to stand and from what height. They would raise the camera to their eye, frame their shot, choose what to focus on, and press the shutter button. They've made a dozen small decisions that have already manipulated the image in a way that will only show part of the scene in front of them. This may or may not be representative of the scene you saw when standing right next to them. They may have noticed details in the scene that you never even saw or they might have missed details that were obvious to you.
Let's say that in the scene we are imagining the resulting photograph shows there are firefighters about to pull their hoses off their truck to begin spraying water into the building. There are people hanging out the windows who look like they are screaming for help. If the photographer captures that part of the scene before them and someone looked at the photo, they might assume it was a scene of brave firefighters attempting to save the building and rescue it's inhabitants. But, let's say we are standing next to the photographer and we have the ability to look around the scene. We look over to the left and there is a big film camera, we look to the right and there is a chair with the words "director" on the back of it. Off to the side we see big lights pointing at the firefighters. Suddenly we hear the words yelled out, "Quiet on the set; and Action!" It is pretty obvious we are witnessing not a real fire but the set of a movie or television show. What the photograph captured was reality, but only one part of reality. This is an obvious example of how a photograph is a manipulation right from the moment it begins to be created. There are more subtle things that affect the "reality" of a photograph however. Something as simple as standing two feet from your subject when you take the picture versus taking it from twenty feet back will dramatically affect the look of your subject.
The same thing goes for any adjustment made to a photograph, whether it's to make someone a little thinner, to remove a reflection from a necklace or eyeglasses, or to remove (or add) a wrinkle from a dress.Now, let's go to another simple example when photographing people. Sometimes you need to alter a photograph to have it appear more real. When you are having a quick conversation with someone, your eyes move around, there are distractions, you might look at the person's eyes for a moment, then toward their mouth, down to their clothing, off to something else that caught your attention for a moment, then back to their eyes. You're also, hopefully, paying more attention to what the person is saying then what they look like. All these eye movements and distractions cause you to not pay attention to minor details. Sure, you might observe certain facial or body features that really stand out, especially if you just met them, but how often do you pay attention to little details on someone you've known for a while, little things like if they are a pound heavier or lighter than they were yesterday or that they are wearing a different belt then they wore last Tuesday. Some people notice more than others but all these little things typically just go unnoticed to the eye. With a photograph however, there is no movement, no conversation that distracts. It's just you staring at an un-moving thing. You can analyze every blemish on the persons skin, every fly away hair, the way the clothing conforms to the persons body. If you were talking to someone who had a particularly dark freckle on their cheek you might not have even noticed it. Or, maybe you did when you first met the person but after knowing them for months you probably don't give it a second thought. In a photograph however that little freckle might stand out and detract from the eyes, which is what is usually the focal point of a portrait. A photographer might lighten the freckle so it doesn't grab the viewers attention not because they have a problem with freckles, but because they want the viewer to focus on a different part of the image.
Now, let's go back to the understanding that photographs are taken for different purposes. A camera can be used as a method of recording something and that will likely be as close to reality as a photograph can ever be. Opposite of that is to utilize the image formed in a camera as one part of a creation that will be completely manipulated by an artist. Perhaps multiple photographs will be combined and software will be used to completely alter the components in the image. Those uses and everything in between will have different amounts of manipulation or "photoshopping" done to them and it will be up to the photographer and their client, if there is one, to have a conversation about how much manipulation they want or don't want. This is nothing new, painters have done the same thing for generations when hired to paint portraits. The people sitting for their portrait would often want to be painted to look a little more attractive, a little taller, a little stronger, etc. Sometimes, the painter would even alter the look of the person to appear more like themselves, you can read about that at The Guardian.
So, whatever you personally think about photographs and "photoshopping" them, you'll hopefully now have a better understanding that this is nothing new, there can be very valid reasons for it, and even if an image doesn't have any manipulation being done to it in an actual computer program like Photoshop, the photo itself is the product of many decisions and manipulations along the way starting before the photographer ever picks up the camera.