ORG means ORiGin(al). Well, this keyword enables you to define where your program starts. The following program starts at $6666, so you can run it with SYS26214 (or SYSDEC("6666")).
You have the opportunity to readdress (reORG) your program inside. This is useful when your program starts for example at $1001 and you would like to use the graphics (it's about from $2000 to $3F3F: 320x200/8=8000=$1F40), but the program doesn't fit between $1001 and $1FFF.