These are tools used to optimize a campaign's performance.
Whitelisting is an inclusionary tool, meaning that when certain parameters within a parent group are whitelisted, only those whitelisted parameters will be targeted. Whitelisting any additional parameters will then include the new parameters in the campaign targeting white list. Only those parameters on the campaign white list will receive traffic.
Blacklisting is an exclusionary tool, meaning that when certain parameters within a parent group are blacklisted, they will not receive any traffic at all. All traffic will be directed towards non-blacklisted parameters. Parameters on the black list will receive no traffic.
Bid overrides is an extremely important tool to ensure campaign profitability. Using the bid override feature, you can alter the bid that will be entered based on individual parameters. So if you find a given phone model has been extremely profitable and you want more of that traffic, you can increase your bid for that specific model to increase the amount of quality traffic that you receive.