A float is a datatype in programming which is a number. But instead of being a full number, it has a decimal.
A float is a smaller version of a double, which is decimal number, with more bits. For example, in C# a float is a 32 bit number, whilst a double is a 64 bit number.
Languages like javascript group floats / doubles together with intagers / long under the Number type. But in most programming languages this is not the case.