Whats the math behind concentration checks?

[A Distraction]

Its pretty nebulous to new players how concentration actually works to someone who's never played 5th edition (like me : P). I did some cursory research and would love to know if the rules are true to 5th edition.

aka getting hit requires a CON save of 10 or half the damage, whichever is greater

It honest to god feels like shadowheart drops more spells than she should, but given the nature of the game its hard to tell if its just bad RNG or if something is funny.

[Srafa]

The DC is 10 + the spells level. so if you cast a level 5 concentration spell the DC is 15. and the check should just be a normal CON check + concentration bonus if you have any etc.