Why have I been charged a service charge?

Excuse me, could you please explain why I've been charged a service fee? I'm not entirely clear on the reason behind this charge, and I'd like to understand it better. Is it a standard fee for all transactions, or is it specific to my account or the type of service I'm using? Additionally, is there any way to avoid or reduce this fee in the future? I appreciate your help in clarifying this matter.