By liking a project, you register to its news feed without financially sustaining it. You will receive all news and updates from the project owner, in order to follow the advancement and news of the project.
To like a project, click on the heart shaped icon in the icon list at the left of the main image / video of the project:
Just keep in mind you won’t receive the news dedicated to the users who contributed to the project. You can’t get everything!
Also, project owners will be very thankful if you share their project to your networks. Promotion is as vital as collecting funds.