Hey there @Mohamad86128 - great question! Thanks for posting this topic. Firstly, check out our New User Guide - it’ll def prove helpful as you get used to the platform!

Now, let’s dig into the nitty gritty of event type notifications! 

Firstly - we have invitee booking notifications. These consist of the choice between email confirmations and calendar invitations - specific to each even type. This is the case on all plans, free or paid. For some context, let’s go over Email Confirmations & Calendar invitations.

1. With Email Confirmations, Calendly sends the invitee an email notification from notifications@calendly.com and has a reply-to address that's associated with your Calendly login email. You can modify this on Account Settings page.
2. With Calendar Invitations, your connected calendar sends the invitee a notification of the booked meeting which has a reply-to address that's associated with your Add to calendar email on your Calendar Connection page.

Note: Calendar invitations are not compatible with iCloud Calendar or the Outlook Plugin (for Windows users). Users with either of these calendar connections set up as their "add-to calendar" on their Calendar Connection page will be defaulted to Email Confirmations. 

Secondly - we have reminders in the form of Workflows. These consist of SMS reminders and email reminders, SMS and email followups and additional SMS and emails that can be set up to send out at different intervals depending on the settings you put in place. Workflows require a paid plan (Standard or Teams). You can read more about our plans, pricing and features on our Pricing Page! Note: an annual subscription will result in a 20% discount for all paid plans! You can read further about our workflows below: 

In short - if you’d like to remind your invitees that their meeting with you is coming up in X amount of time (24 hours? 1 hour? 10 minutes?) you will need to be on a paid plan. That said, invitees will always receive a notice of booking via confirmation. I hope this helps!

FYI - I updated the title of your topic so that it will be easier for others to bring up in a search! =)