What is the difference between a digital keyboard and a digital piano?

It is relevant to notice that people often use synonyms for describing these instruments, such as digital keyboards and digital pianos, but there are differences between those devices. Here are the key differences between them:

1. Purpose and Design

Digital Piano:

Digital piano is intended for the user to feel like they are using an acoustic instrument. It generally aims to produce a feel and sound that is as real as can be imitated.
It is designed especially for piano and most often is used by those who are already more professional musicians or the ones who are studying piano.
Electronic keyboards are usually 88-key keyboards that simulate an acoustic piano’s weighted keys, with functions such as the GH3 weighted hammer action system (where the keys are heavier in the bass section and lighter in the treble section).

Digital Keyboard:

A digital keyboard is a much more complex and diverse instrument, as it is planned for use not only for piano playing but for other genres of music as well. They are for the most part made use of by singers and instrumentalists in popular music or pop, rock, and electronic music, most especially.
There are also choices with digital keyboards, such as the type of instrument sounds, rhythm and even some special effects.
Midi keyboards differ in having more numerous keys (for instance, 61, 76 or 88) and non-weighted keys. Even though some keyboards may come with weighted keys, they are not really made to imitate an acoustic piano.

2. Key Action

Digital Piano:
The most important thing in digital pianos is the touch, or weighted keys, intended to replicate an acoustic piano. This is very important in order to get proper piano technique, as the key diminishes resistance and response like an acoustic piano.
Most of the digital pianos have the graded hammer action or similar features to produce a variable mass of keys across the keyboard (the bass is more massive than the treble).

Digital Keyboard:
Digital keyboards generally have non-weighted or lightly weighted keys and are generally much lighter than that of a digital piano. This is less practical for real playing and is easier, particularly for beginners and is more appropriate for synthesizer players but lacks the back feedback or back pressure of real acoustic piano.
Some of the higher-end models can come with semi-weighted or even fully-weighted keys, and while this does add to the keyboards, they are not as advanced as the keyboards of a digital piano.

3. Sound Engine

Digital Piano:
In a digital piano sound generation, the emphasis is put on using genuine piano sounds; this is either by use of samples of acoustic piano or by employing sophisticated modeling.
Digital pianos concentrate on recreating an acoustic piano and tonal quality, including string resonance, damper effects, and collections.

Digital Keyboard:
Digital keyboards normally feature a rich package, including the number of instrument sounds besides piano. These can include organs, synthesizers, strings, drums and so on and so forth, but the main issue here is that it destroys the logical buildup from one section to another.
Synthesizer presets may be incorporated into keyboards and this can encompass trumpet sounds, guitar sounds, acoustic drums and strings, among others. Other keyboard effects may include the bass pedal, drum pedals and sound effects, among others, designed particularly for electronic music or band performances.

4. Pedals

Digital Piano:
A digital piano typically has a set of pedals—sustain, soft and, occasionally, sostenuto, like the acoustic piano. They are necessary for getting the best feel of what it is like to play an actual piano at home.
Premium digital pianos also have a feature that allows the tweak on the feedback sensitively, similar to an acoustic pedal, depending on the pressure placed on the same.

Digital Keyboard:
In fact, many digital keyboards come or are de facto wipedals, or the pedals are not very functional. If pedals are included, they are normally simple and usually contain only sustain functionality.
Some fold-backs and portables might have pedals sold separately, and even when included, they could not contain the sophisticated features of a digital piano.

5. Portability and Features

Digital Piano:
As a rule, they are larger. Used for permanent placement in a living room or music studio. They are not as portable as an acoustic piano, but they are relatively portable in that you would need a van to transport one.
They generally come with fewer additional functions, for example, built-in rhythms or sound options, because the main function of these items is to play a piano.

Digital Keyboard:
These digital keyboards are often portable, lighter weight and considerably smaller than their acoustic counterparts and are very suitable for musicians on the move, especially those that require a vast number of options.
They also come with additional features such as asording options, in-built rhythms, sequencers, and midi. Keyboards are for different kinds of music and ideas.

6. Price Range

Digital Piano:
Digital pianos are more expensive than digital keyboards in general, especially in terms of a better key feeling and better sound modules. This is the case because they are designed with piano-like attributes and the technology to mimic an acoustic piano.

Digital Keyboard:
In most cases, the digital keyboards are cheaper, especially the simpler ones. But there are also similar models with a significantly high price tag due to more voices, weighted keys, or synthesizer functions, as in a digital piano.

7. Target Audience

Digital Piano:
Southeast of the acoustic piano oriented to professionals and advanced learners as well as to those who prefer practice or performance on an instrument closely related to acoustic pianos.

Digital Keyboard:
Developed for professional performers with keyboards, such as pianists or multi-instrumentalists, who need one instrument, a piano, synthesizer, organ and others. Keyboard instrumentalists tended to choose digital instruments; those who perform, compose, and produce generally need versatility.

Summary Table

In the case of an acoustic or digital piano, you want to be primarily concerned with the feel and sound of the instrument if your goal is only to learn piano or mimic the acoustic piano at that.
The main advantage goes to the electric keyboard because it has a range of sounds and features that allow playing a variety of music genres, making it more suitable for those who play different types of music.