What is Hyperloop?

It is a mode of transport that is (nearly) as fast as a commercial aeroplane and claimed to be as safe/safer than that. It is considered to be the 5th mode of transportation as it differs from any of the existing modes. It is claimed to be better than trains/planes in many ways.

1) Speed

• A new idea is useless unless it is much faster than conventional trains. The hyperloop uses air-suspension (imagine a hovercraft) for the passenger capsule inside a partially evacuated tube.
• This way, energy loss due to friction and drag are minimized.
• Propulsion happens at various sections along the track by means of linear induction motors (Similar to the conventional motors but instead of rotary motion, the same principles are used to generate a linear motion). This makes it fast and cheaper than a magnetic-levitation model which required significant construction in addition to some rare earth elements.

2) Cost

• The proposed budget for the project is $6B which is roughly one-tenth of the California High-Speed Rail Project's budget.
• The operating cost too is cheap as it coasts along for about 90% of the travel time (Remember linear induction motors are used only at certain sections of the track to accelerate).
• Moreover, the 'tubes' inside which the capsules travel are covered with solar arrays and Musk says they produce more power than that is required to run the system. That makes it self-sustaining.

(Source: http://www.teslamotors.com/sites...)

3) Safety and convenience

• It has been meticulously designed to withstand all weather conditions and even earthquakes.
• Passenger safety has been promptly addressed with various measures (I am not mentioning them here to not make this answer unnecessarily long). The fact that the entire travel time from LA to SF is less than the time you would take to board a plane should give you an idea that not many safety concerns should arise.
• A 30-minute travel time from LA to SF and it starts whenever you are ready. Need more convenience?

4) The Best Part

• It is made opensource and that will ensure the hyperloop is further improved a lot before its implementation

(Information Source: Hyperloop alpha)