Public attributes/methods

Hello Experts,

Please allow me to bring here in this forum a question on which I am very curious upon.

As a matter of fact we know that in ABAP OOPs, public attributes/methods can always be accessed from outside the corresponding class.

However, my question is, can these attributes or methods be called from non-SAP systems, i.e., from legacy systems ? Of course there needs to be a connectivity between SAP and non-SAP system.

If the answer is yes, then is this how in BAPIs, BOR interacts with non-SAP systems?

Kindly let me know as your valuable response will be much appreciated.

Kind Regards,

Souvik