Text Editor Tags

Hello Wordpress StackExchange,

I'm embarrassed by what is probably a rookie question, but here it is:

I migrated and took over a website that a friend hired another developer to create, but I don't recognize these tags (main, article, equalizewrapper). My question is, are they built into WordPress, or maybe are part of a customized theme?

I couldn't find any information in my Google searches for equalizewrapper.

Thanks in advance.

Sample code below:

[main]
[article]
  [equalizewrapper class=row full]
    [equalize class=large-8 columns orange-bg contact-padding-1 right]
      h1 class=big-headerContact %COMPANY%/h1
      [contentinner class=large-12 columns strip-padding contact-form]
!-- Normal HTML / CSS was in here --
      [/contentinner]
    [/equalize]
    [equalize class=large-4 columns contact-bg-1 left]
      span class=scroll-trigger side-accent-line inner/span
    [/equalize]
  [/equalizewrapper]
[/article]
[/main]