An array of 32-bit single precision floating point numbers.
Note that despite the "Float" in its name, FloatArray does not hold a sequence of SuperCollider double precision floats, but rather 32-bit (single precision) floats. For a raw array of 64-bit floats, use DoubleArray.
FloatArray and its subclass Signal are commonly used to hold audio data in SuperCollider. Since almost all audio has 16-bit or 24-bit precision, using double precision floats for this purpose would be a waste of space. In other words, FloatArray is meant for storage of large amounts of lower-precision data, but it is not meant for highly accurate math operations.
The complete list of RawArray types in SuperCollider is: