What does deprecated sign means?

While using Pabbly Connect, you might see the deprecated sign as shown below - Deprecated means a better version of the module has been launched, and we recommend using the new version.
Deprecated actions, triggers or app may be usable, but it is considered obsolete and should be avoided, because it has not been maintained further as the better version of the same is available.
Like in this case, you're seeing the "Spreadsheet Formula" as deprecated. That means we have launched a newer version of the "Spreadsheet Formula" as shown below, which you are requested to use. Note that if you don't update it and continue using the deprecated module, it may still work as it should but it is no longer updated and it may go obsolete over the course of time. We recommend users to update their trigger or action events with the latest versions.