Concurrent users means the number of users online at a particular instant on your website.
In the lite/free plan, we do provide 10 users that can use the chat at a time on your website but there will be iFlyChat branding in your chat like “Powered by IFlyChat. While in our basic plan 60 users can use the chat at a time and there will be no iFlyChat branding.
Please see the link to check more info about our plans: https://www.iflychat.com/pricing.
See the Screenshot of iFlyChat branding in Lite/Free plan: