They are both somewhat alike and somewhat different.
I can see some similarities and some differences too.
Both of them involve (only a single similarity, no differences).
Examples: Better Thesis Statements
Ralph and Jack have very different leadership styles and motivations which leads to the eventual chaos and anarchy on the island.
In order to make a decision between the Honda Civic and the BMW, consider the following criteria: price of the vehicle, average mileage, and price of insurance.
Organizing a Comparison and Contrast Essay
Should I use block or alternating arrangement?
Block: Treats all of the elements for each subject separately.
Alternating: Treats each element with respect to each subject sequentially.
If the comparison is short (a paragraph or two), then the block method is fine.
Alternating is usually preferable for longer comparisons; there is a risk that a block essay will sound like two separate essays weakly connected with a transitional paragraph or sentence.
Good comparison or contrast essays feature the use of indicator words to convey to the reader at any given moment whether a comparison or contrast is being made and the nature of it.