Read on to learn the answers to the questions: What is dynamic range? What is tonal range?
Dynamic Range
DSLRs all contain a sensor to capture an image. The dynamic range of a sensor is defined by the largest possible signal that it can generate divided by the smallest possible signal. A signal is generated by the process of the camera's image sensor's pixels capturing photons, which then are turned into an electrical charge.
This means that cameras with a larger dynamic range are able to capture both highlight and shadow detail simultaneously. By shooting in RAW, the dynamic range of the sensor is preserved, whereas JPEGs may clip the details.
As already stated, pixels on the sensor collect photons during exposure of an image. The brighter the exposure, the more photons that are collected. For this reason, the pixels collecting the brighter parts of the image collect all their photons more speedily than those pixels collecting darker parts. This can cause overflow of photons, which leads to blooming.
DSLRs have a larger dynamic range than point and shoot cameras because their sensors have larger pixels. This means that the pixels have enough time to collect photons for both bright and dark parts of the image without any overflow.
Tonal Range
The tonal range of a digital image relates to the number of tones it has to describe the dynamic range.
The two ranges are related. A large dynamic range combined with an Analog to Digital Converter (ADC) of at least 10 bits automatically equates to a wide tonal range. (The ADC is part of the process of converting pixels on a digital sensor into a readable image.) Similarly, if a sensor with an ADC of 10 bits is able to output a large number of tones it will have a large dynamic range.
Because human vision is non-linear, either or both dynamic and tonal range need to be compressed by a tonal curve to be more pleasing to the eye. In reality, RAW conversion programs or in-camera compression tends to apply a vaguely S-shaped curve to the data in order to compress the larger dynamic range in a way that is visually pleasing in a print or on a monitor.