Re: how do I transfer pictures from my samsung A3 phone to picasa on my computer
Welcome to Android Central! Picasa refers to your Google Photos in the cloud. Google acquired Picasa a long time ago, and essentially changed it to Google Photos. Android devices (usually Samsung) still hold onto the Picasa name for unclear reasons, to refer to photos that are synced with your Google Photos in the cloud.
To upload your photos to your Google Photos, install the Google Photos app, swipe in from the left, tap Settings>Backup & Sync, and adjust the options there. See here for more info: https://support.google.com/photos/answer/6193313?hl=en