The Vim text editor is extensible through plugins, which can be categorized into general utilities, color schemes, file type-specific settings, and syntax definitions.
If your question is not about programming, consider posting Vim related questions at the dedicated Vim Stack Exchange site.
The Vim editor can be extended through plugins, which are (at least partly) implemented in Vimscript.
Plugins may add a new color scheme, syntax highlighting for a new language, or settings and commands specific to a particular file type. But most plugins offer general add-on functionality that either enhance the use (like the various buffer and file explorers), or integrate with related tools (like revision control systems).
The main repository of Vim plugins is at vim.org. There's a prolific community of plugin authors and a wealth of different plugins. Some plugins are only available on sites like Github or Bitbucket.