helm and ivy

Helm and ivy are two very popular emacs packages, that for the most part does the same thing. They provide partical completion / search stuff. Like for example when you tyype M-x. Helm is bigger, heavier and slower. But it works out of the box, and the initial setup is much easier. Ivy on the other hand feels much faster, but requires more config. Most people probably start with Helm. I used it for a long time, but once I got into it and figured out the config I greatly prefer Ivy because of how snappy it is