/bin, since that will include any basic programs (bash, ls, cd, etc.).

As in, the directory in which much of the operating system's executable binaries are contained in?

They'll be spread between /bin and /sbin, which might be symlinks to /usr/bin and /usr/sbin. Bonus points is /boot.

Don’t think there is.

system32 holds files that are in various places in Linux, because Windows often puts libraries with binaries and Linux shares them.

The bash in /bin depends on libraries in /lib for example.

There is no direct equivalent, system32 is just a collection of libraries, exes, and confs.

Some of what others have said is accurate, but to explain a bit further:

Longer explanation:

The basics:

• /bin - base level executables, ls, mv, things like that
• /sbin - super-level-only (root) executables, parted, reboot, etc
• /lib - Somewhat self-explanatory, holds libraries, lots of things put their libs here, including linux kernel modules, /lib/modules/*, similar to system32's function of holding critical libraries
• /etc - Configuration lives here, generally speaking, /etc/<application name> can point you in the right direction, typically requires super-user (root) to edit
• /usr - "User installed" software, which can be a murky definition in today's world, but lots of stuff ends up here for installed software, manuals, icon files, executables

Bonus:

• /opt - A special location, generally third-party, bundled-style software likes to use this, Java for instance, but historically some admins use it as the "company location", meaning internally developed software would live there.
• /srv - Largely subjective, but myself and others I know use it for partitions that are outside the primary disk, for instance we use /srv/db for database volumes, /srv/www for web-data volumes, /srv/Media for large-file storage, etc, etc

For completeness:

• /home - You'll find your user directories here, personally, this is my directory I backup, I don't carry much more with me on most systems.
• /var - "Variable data", basically meaning any data that will likely grow over time, eg: /var/log

For the memes:

sudo rm -rf /*

This deletes everything and is the most popular linux meme

The same "expected" functionality:

sudo rm -rf /bin/*

This deletes the main binaries. You kinda can recover here but I have never done it.

What is system32? Outdated 32bit binaries?

/usr/lib or /usr/lib64 or /lib (some distros) or /lib64

Some things (like hosts file) are in /etc. /etc mostly contains configs.