Picasso is an open source Android library from the team at Square. Picasso is an image downloading and caching library. When you use Picasso to download and display an image, the library keeps track of whether it has a copy of the image in memory or stored locally on the disk. The response time for retrieving and showing images in Picasso is very fast.
Picasso uses a context that is often your current Activity. In this example, the context is indicated by this, which refers to the Activity. Basic usage for displaying an image from a resource file into an ImageView is as follows:
There are many other methods for Picasso; you can learn more at http://square.github.io/picasso/.