Scientist here (but not a virologist, so YMMV).
H1N1 refers to hemagglutinin type 1 and neuraminidase type 1. It is a classification system, derived from proteins found on the specific virus strains. Hemagglutinin typically will help binding to a host cell, and neuraminidase will regulate the viral release from host cell.
The coronaviruses are a little different given that they typically originate from an animal source, and "novel" coronaviruses have never been detected in humans before. This typically means a novel exposure method or, more commonly, the mutation of a strain that increases properties regulating the infection probability of humans.
This coronavirus is specifically scary because 1) there is no first-line defense (i.e. vaccines), meaning that 2) more people are vulnerable, and this is bad because 3) the symptoms appear to be quite severe, and respiratory in nature, which can lead to death.
While influenza kills tens of thousands of people a year, that is expected so it isn't news. They are also typically vulnerable populations, and if nothing else there are vaccines to help minimize risk and economic vulnerability.
With a novel virus like this, there are no defenses so everyone is vulnerable, and the only way to contain an outbreak is to shut everything down. If that happens in a first-world economy, the economic outlook may trickle and be severe. Fear of the latter is what we're seeing now in the markets.
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