Is there any difference between private/public variables for application security?

[leaden swan]

Is there any difference between private/public variables for application security as in are public variables easier to manipulate for someone trying to exploit a program or is the difference purely for my own code hygiene and making sure things that shouldn't interact dont?

Is there any difference between private/public variables for application security?

[slim cradle]

no

[scarlet skiff]

not at all