logical read vs actual row count

Hi

Can someone tell me what the difference between the logical read from statistics io and the actual row count from actual execution plan. I have a query that has the following

statistics io
Scan count 1, logical reads 484

actual execution plan
Clustered Index Seek
Actual Row Count : 40067

does this mean that sql has to read 484 pages from disk, and that 484 pages has over 40067 rows?

I wrote my query another way, and numbers becomes

statistics io
Scan count 1, logical reads 1207

actual execution plan
Clustered Index Seek
Actual Row Count : 133

the 1st query took about 2 seconds, but the seconds query took about 4 seconds. does this mean the logical read is more important

thanks

Paul

See SQL Server 2005 Books Online topics:
Reading Pages
http://msdn2.microsoft.com/en-us/library/ms191475.aspx

SET STATISTICS IO (Transact-SQL)
http://msdn2.microsoft.com/en-US/library/ms184361.aspx