Diference between statistics

I have a question here about the PHP list statistics.

When I click on General Statistics, I have the column with the data SENT.

When I join the campaign, there is the SENT AS HTML statistic.

What is the difference between the two statistics?

@pelaestrada The total on the second page (6,538) is the number of attempts to send, whereas the total on the first page is the number actually sent (3,468).

I guess that there have been many failures in sending. You can check this by looking at the Event Log page for any errors reported.