What kind of Spartans are these?

Sorry but I havn’t read the books so I would really like to know more about these spartans. I know Johnson is a spartan 1, MC is a 2, I think some reach spartans were 3s… but now I start losing it. What kind of spartans are we dealing with these days? Also more importantly what does “spartan” really mean now? because obviously you can’t compare ability between a spartan 1 and 2, so are spartan 3s as good as 2s? were 2s the only ones kidnapped as children? were these spartans volunteens? thanks for any help

The Spartans in Halo 4 and 5 are Spartan IVs. Like the original Orion(Spartan I) program they use voluntary adult candidates, where as Halsey’s Spartan IIs and Ackerson’s IIIs were children abductees. You can read more about this in the universe section https://www.halowaypoint.com/en-us/universe/factions/spartans

Edit: I misspoke about IIIs, they were recruited from orphanages, coerced to fight. It’s been a bit since I went through Onyx.

The current spartans I’m presuming are spartan 4’s, as they are in halo 4.
Spartans ones were more of just a test to see if the human can be configured in such a way. Spartan 2’s are as you know, survivors of the program, I think it was 72 children kidnapped, 35 spartans were made. Somewhere around those numbers. Spartan 3’s were orphans who volunteered for the training during the human-Covenant war. They had the training and injections but not the ceramic bone implants, these spartans were more or less made as quickly as possible and sent on suicide missions, sent in as young as 12 years old. The spartan 4’s are soldiers, who already have experience and have shown great skill in combat, chosen to become a spartan, given the upgrades and implants.