What are the differences between Acrobat and Preview?

As you are running OS10 you will be getting an increasing number of Bank issues. The recent changes that make the bank liable for people being scammed will mean even more of their applications are hardened. Whilst this is a Good Thing on the one hand, it's increasingly tiresome when a perfectly serviceable but elderly device can no longer do its job of replacing a bank branch.

Adobe acrobat is/was very leaky, and since they made it capable of doing more than present a document it has become another security hazard. You do not mention how these documents are presented, or where they are from. After scrutinising the source (and if it is email, do not trust the visible headers) if you decide that you should investigate further, check out the many dozens of PDF readers available, and locate an open source version to use.

R

many web browsers like firefox are also fine pdf viewers and support overlay edits too

never use acrobat it's a product which often needs updates to fix security issues

your bank says .. but have you so far experienced issues opening their files? if not then suppose you need not worry

Apple's Preview is a PDF reader that is based on quite old PDF specifications and Adobe Acrobat Reader is kept current with the evolving modern PDF specification because Adobe originated the PDF specification. Apple would have to pay exorbitant royalties to Adobe to modernize the PDFKit framework upon which Preview and many applications have dependencies. It would be a quagmire to update at this late date.

Most of the PDFs you will encounter on macOS can be opened by Preview. There are a few that may have internal PDF dependencies that only Adobe Acrobat Reader can process. PDF form fields may have attending Adobe Acrobat JavaScript coding which Acrobat Reader processes and Apple's Preview simply ignores. Firefox v131.0.3 and Brave 1.71.118 browsers support Acrobat JavaScript in their built-in PDF support.

I keep a current copy of Adobe Acrobat Reader installed and updated. There are more reasons to do this than simply security updates that Adobe provides periodically. There are also times when I wish to apply a true yellow highlight to PDF text and Acrobat Reader provides a means to do this via a color wheel.

Here is Firefox respecting a PDF containing Acrobat JavaScript:

What "bank software" are you using? Is it an app on your Mac, or are you getting this message in a browser window when you are logged into your bank account?

Your profile indicates you are using macOS Catalina 10.15. There really shouldn't be a problem viewing PDF files on it regardless of using Preview vs. Acrobat.

ps. I have never encountered a security issue with either Preview or Acrobat.

Acrobat is a third party PDF viewer and "editor" developed by Adobe, the makers of the Photoshop application.

Preview is Apple's built-in image and document viewer, and yes it supports PDFs.

As previously mentioned, some more complex PDFs may not open correctly or at all in Preview.

There are however alternatives to Acrobat and Preview to view PDFs.

Unless your bank is sending you complex PDFs for some reason, Preview should be in almost all cases enough.