Your Personal Meeting Room is a virtual meeting room permanently reserved for you that you can access with your Personal Meeting ID (PMI) or personal link, if applicable. You can start instant meetings with your PMI, or you can schedule a meeting that uses your PMI.
Your Personal Meeting Room is ideal for use with people you meet with regularly. However, because it is always accessible with the same Meeting ID and personal link, it should not be used for back-to-back meetings or people you do not meet with regularly. Once a participant has the link to your PMI, they can join it at any time the meeting is in use, unless you lock the meeting or use the Waiting Room feature to admit participants individually.
https://support.zoom.us/hc/en-us/articles/203276937-Using-Personal-Meeting-ID-PMI-
Using an automatically generated meeting ID allows the host to have a unique ID for each meeting. This ensures that a participant needs that unique information to join that individual meeting.
Meeting ID expiration
- An instant meeting ID expires when the instant meeting ends.
- You can start your scheduled meeting at any time after you scheduled it.
- A non-recurring meeting ID (also known as a one-time meeting ID) will expire 30 days after the scheduled date if the meeting is not recorded. You can also restart the same meeting ID within the 30 days and if you restart the meeting, it will remain valid for another 30 days.
- A recurring meeting ID expires if it isn't used for 365 days.
- A Personal Meeting ID never expires.