What are the differences in parallel timeline, alternative timeline, or direct timeline?
Direct is same as our own (no changes). In fact, percent divergence is zero.
Alternate is close to our own maybe 2% divergence. However, who wins the superbowl might be the "wrong" team as Titor said. The point of departure is recent like seven years ago. For example a timeline where Al Gore was elected president, the twin towers still stand and there is no war.
Parallel is just that. It runs parallel to our own. The changes are many, and percent divergence is high, for example, a timeline where WWI never happens so there is no WWII or Hitler's Nazi Germany.
A lot more people are alive on earth, but technology is less. People still in 2008 have vacuum tube B&W TV like our 50's. Central air is rare, but people have tiny wall units. However in some areas there is more technology like electric cars. Remember there were electric cars back in late 1800's and Edison was pushing them.
Using solar and wind power to make electricity means less pollution. Remember wind mills were popular in our 1920's on farms. On the parallel timeline technology takes a different route.
Also socially, people would act different and dress different than here. Like men wearing hats and ties, women wearing dresses. Things moving at a slower pace than here.