Is code belonging to a Financial Institution which identifies it worldwide. It is comprised of 8 or 11 alphanumeric characters. The International Organisation for Standardization (ISO) was the authority which approved the creation of such codes.
SWIFT Code is made by assigning each Financial Institution a unique code. To clarify it in detail, here is an overview of PayAlly SWIFT: PYYLGB2LXXX:
First four characters identify the institution (PYYL)
Next two characters identify the country (GB)
Next two characters the location/city code (2L)
Last three characters are optional to identify the branches (XXX)