Sure - traditionally the Sámi people have been divided into two groups: Those that have lived around / near coastlines ("sea Sámi"), and those more inland (typically just "Sámi", or "reindeer Sámi", "hill/mountain Sámi".

In short, the coastal Sámi people have made their living off fishing, farming, and similar activities.

On the other hand, those living inland have mostly made their money off reindeer husbandry. Reindeers will forage over a large area, and in Northern Norway / Sweden / Finland / Russia that includes large tundra and hilly places - so many of Sámi involved in that trade would trek over and live in these areas.

With that said, these days I think only 5%-10% of Sámi have reindeer husbandry as their main profession.

But the vast majority of conflicts between Sámi people and the rest usually comes down to the reindeer. Since the reindeer need a huge area to graze on, it tends to become a problem for companies wanting to develop the area for industry.

Just recently our supreme court decided that a wind farm had been bult in conflict with cultural landscape of local Sámi people. Reindeer husbandry is a cultural heritage activity, and thus protected. The area reindeer graze on, is thus a cultural landscape, and also protected.

The intra-Sámi conflicts, from what I've seen and heard, boils down to either things related to the reindeer industry - or I guess elitism from the "true" Sámi people toward the coastal Sámi people.