In imperial, a hand is 4 inches, hence the 14, 14.1, 14.2, 14.3, 15hh. In metric, a hand is 10 centimeters. Hence the 14.1, 14.2, 14.3, 14.3, 14.4, 14.5 etc. Some countries in Europe especially don't even use hands much anymore, they use centimeters. So if a horse measures 14.3hh horse in an imperial country, they measure 14.75hh in a metric country (bear in mind that lots of people do still use inches to measure hands in these countries too, but more people will understand what that means), and in Germany for example, they would measure as 147.5 cm.