How does php webservice prevent others from calling it?

How does php webservice prevent others from calling it? Can someone else call these methods if they know the address of your WEBSERVICE? Is there any way to limit it, or is there any verification method available? ------ Solution ------------------ 1. First, define an addition mechanism to decrypt and verify the sent requests. 2. how can we prevent others from calling WEBSERVICE using soap PHP?
Can someone else call these methods if they know the address of your WEBSERVICE? Is there any way to limit it, or is there any verification method available?

------ Solution --------------------
1. first define a certain addition mechanism to decrypt and verify the sent requests.

2. with soap, I remember that only valid users can call the service by adding user warrants.