Overexposure occurs when too much light reaches the camera's sensor, resulting in a photograph that is too bright and washed out.

Underexposure occurs when not enough light reaches the camera's sensor, resulting in a photograph that is too dark and lacking in detail.

Overexposure is primarily caused by too much light reaching the camera's sensor, either due to bright lighting conditions or incorrect camera settings.

Underexposure is primarily caused by too little light reaching the camera's sensor, either due to dim lighting conditions or incorrect camera settings.

Overexposure can be identified by washed-out colors, loss of detail in highlights, and blown-out highlights, where the brightest areas of the image appear completely white.

Underexposure can be identified by dark and shadowy areas, loss of detail in shadows, and crushed blacks, where the darkest areas of the image appear completely black.

Overexposure can be prevented by using a lower shutter speed to reduce the amount of light entering the camera, using a smaller aperture to restrict the size of the opening through which light passes, or using a neutral density filter to reduce the intensity of light reaching the sensor.

Underexposure can be prevented by using a higher shutter speed to allow more light to enter the camera, using a larger aperture to increase the size of the opening through which light passes, or using a neutral density filter to reduce the intensity of light reaching the sensor.

Increasing the saturation is not a common technique for correcting overexposure in post-processing. Instead, techniques such as decreasing the exposure value, adjusting the contrast, or applying a graduated neutral density filter are typically used.

Decreasing the contrast is not a common technique for correcting underexposure in post-processing. Instead, techniques such as increasing the exposure value, adjusting the brightness, or applying a graduated neutral density filter are typically used.

A faster shutter speed results in less exposure because it allows less time for light to reach the camera's sensor.

A larger aperture results in more exposure because it allows more light to pass through the lens and reach the camera's sensor.

A higher ISO results in more exposure because it increases the sensitivity of the camera's sensor to light.

A histogram in photography shows the distribution of tones in an image, from the darkest to the lightest. It helps photographers to assess the exposure and tonal range of their images.

A properly exposed photograph typically has a histogram that is evenly distributed across the entire tonal range, indicating that the image contains a good balance of highlights, midtones, and shadows.