title: Difference between Apache parquet and arrow
body: <p>I'm looking into a way to speed up my memory intensive frontend vis app. I saw some people recommend Apache Arrow, while I'm looking into it, I'm confused about the difference between Parquet and Arrow.</p>
  
  <p>They are both columnized data structure. Originally I thought parquet is for disk, and arrow is for in-memory format. However, I just learned that you can save arrow into files at desk as well, like abc.arrow In that case, what's the difference? Aren't they doing the same thing?</p>