People who work in the sales field are responsible for acquiring sales leads and closing deals. Skills and techniques used within sales are prospecting, outreach, sales management, relationship management, negotiation and customer success.
In a leadership position someone is responsible for a group of people, typically an organizational unit or the entire organization, depending on the size of the organization. Leaders are responsible and accountable for overseeing and guiding strategic activities, programs and managers who report to them. Just a few people in an organization are typically in a leadership role.