Two names, one approach
Factur-X is the French standard for the hybrid electronic invoice. ZUGFeRD is the German counterpart. In the current 2.x series both are technically aligned and compatible.
Concretely: a PDF/A-3 with an embedded CII XML file. That is the case with Factur-X and with ZUGFeRD 2.x. Whoever can process one can usually process the other.
Why there are two names
Historically both arose separately — in Germany via the Forum elektronische Rechnung Deutschland, in France at national level. With the alignment to the European norm EN 16931 they grew together.
The two names are therefore more origin labels than technical differences. For most German companies Factur-X is simply “what the French side calls ZUGFeRD”.
When it becomes practically relevant for you
As long as you only invoice and receive nationally, you hardly need to think about Factur-X — ZUGFeRD covers that. It gets interesting in cross-border business with France.
There the hybrid approach is especially practical: the recipient sees a readable PDF, the software the structured data. A common technical denominator across borders — that is the actual added value.
What you do not have to overthink
You do not need a second software “for Factur-X”. If your intake processes ZUGFeRD 2.x correctly, it processes compliant Factur-X files along with it.
The honest message: do not let the second name unsettle you. More important than the label is whether the embedded XML is norm-compliant and which profile it carries.