Array Basics

[Bojsza]

I am starting to forage into arrays and have some very basic questions:

1. What is the difference between an array and a matrix?

The following script is to take a 3x1 array and multiply it by a 1x3 
array

on mouseUp
   put empty into xArray
   put empty into zArray
   put "1 2 3" into xArray
   split xArray by space -- create an array from a list (3x1 array)
   put "2 3 4" into zArray -- create a 1x3 array
matrixMultiply(xArray,zArray)
put it into arrayOut
end mouseUp

The script editor errors with the following:

Expression: missing ' ) ' before factor.

2. I know that I can go from a list to an array with the split command. 
Can I go from an array to a list also using the split command?

3. Can I create an array with a variable ie a 3x1 array with angle as a 
variable?

atan(angle)
cos(angle)
sin(angle)

thanks,

Glen