JSTOR is a trusted academic resource with high brand name recognition.
For the entire field of psychology, it includes only 35 journals.
On the plus side, coverage of journal titles goes all the way back to volume 1
On the down side, it does NOT generally provide access to the most recent volumes
Google Scholar is a search engine that looks for files on the web that appear to be scholarly.
The availability of content depends mostly upon your library's subscriptions.
You can customize some settings to make it easier to manage search results.