What is auto bid extend?
If any bids are placed within the last 60 seconds, the auction end time is automatically extended for an additional 60 seconds. The auction will close once all bidding activity has stopped for a period of 60 seconds.
What is automatic bidding?
The automatic bidding feature allows you to set a maximum bid amount so you don’t have to keep placing a new bid when someone outbids you. The system will automatically increase your bid to keep you as the highest bidder until your set maximum bid amount is reached. If the current bid goes above your maximum bid the system can not longer bid on your behalf. You will need to place a new max bid to continue in the auction.
Learn more on how this works