Sales automation lets your sales team do several things.  First, it allows them to define email templates which they add to campaigns or cadences.  These cadences are structured and automated.  For example, a rep might send an email, then another the next day, then another 3 days later, etc.  Sales automation automates this process.  It also tracks when leads open or forward emails, or click links within them.  Most sales automation tools provide real time alerts when leads open emails.  Some include integrated click-to-dial dialers which eliminate the inefficiency of manual dialing.  Sales automation software is designed for individual contributors managing hundreds of leads, contrasted with marketing automation tools designed to manage many thousands.