What’s the significance of conversion delay?

It refers to the load time for a page that is used to measure conversion actions on the advertiser’s site — an order confirmation page, for example.
It is the amount of days required for a newly adopted Smart Bidding strategy to take effect after the first recorded online or offline conversion for a campaign.
It is the amount of time that elapses between the clicking of an ad and an advertiser either uploading an offline conversion or completing the conversion on a site.
It is the amount of time it takes an advertiser to create a conversion measurement strategy for their Google Ads account.

The correct answer is:

It is the amount of time that elapses between the clicking of an ad and an advertiser either uploading an offline conversion or completing the conversion on a site.