Email Grabber allows you to use multiple simultaneous connections to make sure that you use your computer and Internet connection to their full potential. This way you can scan several pages at the same time.
This setting allows Email Grabber to scan multiple URLs at once.
The optimal number of simultaneous connections depends on several factors like your Internet connection's characteristics, your computer's specifications and the search you are about to perform.
If your search will focus on a single web site, we recommend using a very low number of simultaneous connections. Making too many simultaneous connections to the same web server may disturb its normal service and the web server may be against the terms of service of each web site.
There is a setting in Preferences called Server Overload Protection that is meant to prevent Email Grabber from making too many requests to the same web server and that may slow down your search on purpose regardless of the number of simultaneous connections.
If your search is broader and you do not expect opening too many connections to the same web sites then you can use a higher number of simultaneous connections.
You should try different settings to determine which one is best for your system's characteristics.