I'm waiting for my EQD to clear to get to requalify EP for next year (currently EP) and should clear by $20 or so, but I want to have a flight in the bag just in case AA makes a mistake in crediting my EQD.

So I was looking into buying a back up flight. I couldn't find the "refundable" option but instead, found the flexible option.
for LAX- PDX, I get fares of $365, $1127 and $514 for Main Cabin Flexible vs Main Cabin Fully Flexible vs First Flexible, respectively.

I understand that the Main Cabin fare is likely fully refundable, but not sure what the other two classes Main Cabin Flexible or First flexible mean in terms of cancellation or refund.

Any clarification about these what these fares mean would be appreciated.