There is some crossover. Inversions (and root position) will tell what note is at the bottom - in C major triad, C as bass will be root, E as bass will be 1st inversion, and G as bass will be 2nd inversion. It matters not which order the other two are, above the lowest note.
The more notes added to that triad (7ths, 9ths, 11ths, 13ths, and their ♭/♯ alterations), the more inversions there can be. Obviously, with a 5 note chord, there are 5 different choices for which note is at the bottom. Again, order of other notes (or even lack of them) won't affect the naming of that inversion. Some may not sound good - but that's a different kettle of fish!
Voicings - open or closed? Closed voicings occur when each and every note is as close to the next (up and down) that it can be. Open voicings use whatever notes are appropriate, but will not use every consecutive note from that chord. All voicings are subject to root or inversions. They can have any of the approriate notes, in any order. They can double or treble certain notes. On guitar, it's common on chords such as open E to play three root notes.
So, whilst being closely related, they're not the same, although they do both contribute to information about a chord, they are not synonymous. Every voicing will also have a label for its inversion, but an inversion tells us little about the voicing.
Check out slash chords, drop voicing. And be aware that in certain circumstances, 3rd, 4th, 5th inversions won't necessarily sound good. In others, they work really well...