Both in the way it feels to play and in the sound produced, digital pianos are designed to serve primarily as an alternative to a traditional piano. Some digital pianos are also designed to look like an acoustic piano. While digital pianos may fall short of the genuine article in feel and sound, they nevertheless have many advantages over acoustic pianos:

• Compared to new acoustic pianos, digital pianos are generally less expensive.
• Most models are smaller and considerably lighter.
• They have no strings and thus do not require tuning.
• Depending on the digital piano, they may include many more instrument sounds including strings, guitars, organs, as well built-in rhythms and accompaniments, and the ability to record and play recorded music, and much more.
• They are much more likely to incorporate a MIDI implementation.
• They may have more features to assist in learning and composition.
• They usually include headphone output.
• They often have a transposition feature.

In addition to a superior sound and touch, an acoustic piano has its set of advantages as well:

• Digital pianos use sampling technology to reproduce the sound of each piano note. However, with such technology, it is difficult to duplicate a crucial aspect of acoustic pianos, namely that when the damper pedal is depressed, the strings not struck vibrate sympathetically when other strings are struck, as well as the unique instrument-specific mathematical non-linearity of partials on any given unison. Since this sympathetic vibration is considered central to piano tone, many digital pianos do not sound the same as the best acoustic pianos. Some higher end digital pianos, such as the Yamaha Clavinova series, produced in the last few years incorporate string resonance technology to overcome this limitation.
• A digital piano will never sustain notes for nearly as long as an acoustic piano can.
• Realize that beyond a certain level, some piano teachers will not teach students who have learned on anything other than an acoustic piano. Digital pianos are frequently counterproductive when it comes to technique and dynamic performance. These skills cannot be practiced on a cheap digital keyboard and later applied to a real piano. An acoustic piano generally represents a stronger commitment from a student.
• Don’t forget about investment value. Consider that an acoustic piano will hold its value far better than a digital unit. An acoustic piano can last 100 years or more, while a digital piano may be obsolete in 5 years. An outdated keyboard is often difficult to sell.