Offshore generally means you're trying to slash costs. Say, hiring $10/day devs from India. Now, there are great devs in India, but they don't work for $10/day.
It's the same term that was used for transitioning textile and other factory work to third world sweatshops.
Hiring internationally is just that. You might get someone for a bit cheaper (somewhere in the neighborhood of 20ish percent), but that's usually in exchange for the extra hassle of managing a remote team and dealing with timezone issues. You don't usually crank through these people every quarter, they're hired for the longterm (or, as longterm as anyone in a software job is hired for).
I worked on a team with two other engineers. I was in the EU, one was in Australia, and one on the west coast of the US.
We had very, very little overlap to have meetings (unless one of us wanted to wake up early or have a late night meeting, which happened a few times). We did everything async, even meetings and decisions.
The best part would be learning how to open a WIP PR, with enough detail that someone else could understand what you were going to do. You'd wake up in the morning to find a team member had contributed to your PR, either by fixing nits (we didn't have time to go back-and-forth on shenanigans or it would take weeks just to merge a single PR), or by actually implementing some idea they had. So, if you didn't like it, you'd just remove that commit from your PR.
I had the "timezone thing" with a colleague in the same city because he had some weird sleep disorder. Basically, he was a vampire. Asleep during the day, working all night.
It was awesome. I'd turn up to the customer site to collect their issues and requests, do some investigation, formulate the precise requirements, and send it off to him.
The next morning, magically, things would be done.
When you offshore cost is the main factor and the companies optimise for it. As an example you may have an offshoring contract with Infosys where you pay around $20/hour/head and they provide mostly freshgrads (some times referred to as "commodity developers") with dubious qualifications. But you can say you have 100 engineers on the project. When hiring internationally you usually hire and interview a specific person and pay them well through Deel (or equivalent). All of the former engagements have been a disaster, the latter have mostly worked out.
Both have their benefits. In my experience offshore teams are basically an army that you need to train and provide a lot of direction. It can be very frustrating but if you have code generators, Sonarqube, linters and they are only working on CRUD applications it sometimes works out. Whereas international hires are usually very competent because you personally selected them.
To me, "offshore" means acquiring developers from international shops that bid for US contracts, whereas hiring internationally just means hiring outside the country on an individual basis.
Speaking very broadly here, my impression is that those offshore development shops bidding for US contracts often don't have the greatest working conditions. Those talented enough to know their worth and find better options will do so if the opportunity presents itself, which could mean either applying for international positions on their own or immigrating to where the jobs are. Thus there's an outflow of talent away from those offshore companies.
Offshoring is contractors. They (usually) will code exactly what you tell them, and no more. They are not "product oriented" and won't push back on things if they make no sense -- they'll just shake their heads and get it down in the fastest way possible. They are not here "for the mission" and often don't care about maintainability. It's not their fault, they know they could be let go at any time, and any personal relationships they might build in the company won't save them come budget time. So you know, they're kind of checked out. On top of that you have timezone issues and potential language barriers.
Hiring internationally, you might have TZ and language issues but none of the other stuff. If you do your hiring right that is, you'll get somebody who actually wants to be part of the team and is product oriented.
I think the poster is hinting at skill level, where "offshore" is low skill in a cheap location, and "hiring internationally" means high skill in any location (or provide visa to move to high cost location).
One thing that I have found with "offshore" hiring: The very best have _mostly_ migrated to high cost locations because they get a huge salary increase (far more than cost of living increase). There are _some_ exceptions where the candidate is very high skill, but needs to live in a developing country. Usually family or cultural reasons. However, they are very hard to find and harder to keep.
The difference is only implied in their comment. They are using "offshoring" to referring to relying on a completely outside team to deliver a product.
In comparison to hiring individuals internationally to work with an internal team.
In the first case the entire project is "offshore." In the second case only individual team members are not in the primary country.
What would be the difference between offshore and hiring internationally?