An even more powerful search with the PRO version

Multiple (unlimited) different search instances with different configurations
Powerful Index Table engine - to handle fast and accurate searches for even big databases
Post types, Taxonomy terms, Files and File contents, Users, BuddyPress Groups as results
Vertical, Horizontal, Isotopic and Polaroid layouts
Post type, Generic, Content type, Taxonomy, Custom Field (including ACF) and Date filters
100+ Themes, fully customizable
Taxonomy, Tag, User, Date, ID and other result exclusion and inclusion methods
Individual and results group prioritizing options
Powerful API for both the server side and the client side, as well as a REST API
..and many other features, check the full features list.

The Lite and the Pro version are two separate plugins, thus you can switch from Pro to Lite and vice-versa at any time, without loosing your settings.