Speed up import of mysql database with this simple trick

I was doing a trial run of importing a moderately big database on my local machine and it was taking almost forever. I found out this tip by someone that worked like charm. Try this out

mysql> use db_name;

mysql> SET autocommit=0 ; source the_sql_file.sql ; COMMIT ;

It not only showed me what's happening, but also did a world of difference to the speed of import!

PS: I'm not into databases and not sure what magic does autocommit=0 does. Would love if someone can explain in easy to understand words.