Whom to invite to marriage?

Whom to invite to marriage? What’s the general SOP when it comes to inviting your friends, colleagues & ex colleagues to marriage? I understand the family , relatives & neighbours are sorted as our parents take care of it. How are people in this gen going about inviting their connections? Is there anything like checking the last connected time or something? I am seriously wondering, there were super close friends in schools & colleges and we have not talked in years. Do you invite your clients anol?