Easy-PC has a built in function so that a record is kept of several previous versions of any design.  This is accessed from the 'General' tab under [Settings], [Preferences].
When you look at this tab, you'll see a 'Design Backups' area near the top left corner, with a number of settings.which are covered below.  In principle, this function preserves the previous copy whenever a manual save is initiated.  The settings configure when this happens, how many are kept and where they are kept.
The first setting is 'Versions' which is the number to keep.  A common practice for any backup system is known colloquially as the 'Grandfather, Father, Son' method which is simply a way of saying that three progressively older versions are kept, which explains why this figure defaults to '3', but you can set it to any number you require up to a maximum of 10 copies.  The newest backup will use the design name with the suffix 'BAK_1', then 'BAK_2' and so on.  When a design is saved, it is initially saved to a temporary file for security.  The oldest backup is discarded and each previous one renamed with the number being incremented.  the old design is then saved to 'BAK_1' and the temporary file renamed to the design name.  This method ensures that no data is lost in the highly unlikely event of a machine failure during the process.
The next setting is the location of backups.  Whilst the default is to save with the design file, this can create a very cluttered working directory, so options for a named subdirectory below the design one (which will be automatically created if it doesn't exist) or a specific location are both available.  Both have their advantages but either will help to keep the design directory free from clutter.
The 'Min work time between backups' is a setting so that if you're saving frequently the program can be set so as to not update the history.  This can be important,  With the complexity of current software and machines, despite any inbuilt protection, random corruption is a fact of life, though thankfully rare.  However, should a design become corrupted, if you're saving frequently, you could inadvertently save a damaged copy to all your backups as well.  This provides a safety net, so backups are not updated unless a minimum amount of work has been done on them.
The 'Idle time before stopping work'  provides a buffer so that should you pause for a short while, the work time timer won't reset immediately.  The setting will depend on your style of work, so it's not possible to make any recommendation as to the value.  You do need to be cautious with your choice, as if the duration is longer than the work time setting, any operation triggering an 'Undo' record will also cause the minimum work time to be exceeded so a backup will always be created.