When you open a new file to analyze, ida automatically creates a .idb archive database. This archive contains four files namely:
name.id0 – contains contents of B-tree style database,
name.id1 – contains flags that describe each program byte,
name.nam – contains index information related to named program locations,
name.til – contains information about local type definitions
These files can be independently used for further analyzing without a need to have the original executable.
These file formats are proprietary and can be used only on IDA. But if you are on a demo version of IDA, you wont be able to save your work.