To answer the original question,
For installing packages, PIP and Conda are different ways to accomplish the same thing. Both are standard applications to install packages. The main difference is the source of the package files.
An important cautionary side note: If you use both sources (pip and conda) to install packages in the same environment, this may cause issues later.
Best practice is to select one application, PIP or Conda, to install packages, and use that application to install any packages you need. However, there are many exceptions or reasons to still use pip from within a conda environment, and vice versa. For example: