Google’s search algorithm is always being improved. That being said, Google only releases updates and changes to their algorithm every so often. Last year, they released an improvement known as Pigeon, which sought to improve search ratings on local sites
Here’s an interesting piece of information you should be aware of as we head into 2015: Google changes its search algorithm around 500–600 times every year. As Moz points, however, that’s nothing to be worried about. Most of the time these are minor changes, but every now and then Google shakes things up significantly – think Google Panda and Google Penguin.