single file opens as ( file.ai:1 file.ai:2 ) - not sure how I did this IMG provided

[Dallas$egno]

can someone explain how I did this, what it is used for? I have no idea how it happened. and if I send the file, does it send as two files?

[Ton Frederiks · Accepted solution]

You opened a Window > New Window for this file and saved it.

[Ton Frederiks]

Which can be usefull; one window zoomed in to edit a detail., the other zoomed out for an overview.

If you close one and save the file, you will have one window when you open it the next time.