-He has 6 item slots
-If he gets posioned by Yawn (Giant Snake) Must play as Rebecca to get the serum
-He has Rebecca get the V-jolt, then fights Plant 42 manually
-He gets a flamethrower to deal with Black Tiger (Giant Spider)
-He has a lighter on hand (used to burn incapitated zombies so they don't turn into Crimson heads)
-He is much better with weapons (handles them faster IE; aims slightly quicker, gets more crits etc)
-He has to use Old Keys to unlock things
-He has more health (1400 HP)
-Has Rebecca as a partner (can heal you)
-He starts out with only a knife but quickly obtains Jill's handgun
-He has flash grenades which go off after a few seconds or sooner if you shoot them, exploding a zombies head, acting like a crit and killing them for good (defensive item)

When you first play as Chris, he loses his handgun and only has a knife to use, Jill and Wesker go into the mansion with him and Barry is nowhere to be seen. They hear a noise and Chris goes alone to investigate. When he returns, Jill and Wesker are gone and he quickly finds Jill's handgun and uses it. He later finds Rebecca who becomes his partner.

-She has 8 item slots
-She can avoid fighting Plant 42 entirely
-She gets a powerful grenade launcher later on
-She can grab shotgun very early on without needing the replica (Barry saves her from the trap)
-She has a lockpick (doesn't require Old Keys to open things)
-She is slower and and weaker with weapons (slightly slower to aim, doesn't get as many crits etc)
-She has less health (960 HP)
-She has Barry as a partner (saves her from dying a few times)
-She starts out with a handgun
-She has Stun Guns which make the zombies fall down but are less effective than the grenades and don't even kill (Defensive item)

When you first play as Jill, you start off with a Handgun and a knife, She enters the mansion with Barry and Wesker with Chris nowhere to be seen. They hear a noise and go and investigate with Barry, when Jill and Barry return, Wesker has disappeared and Jill and Barry split up. Barry becomes Jill's partner.

Jill and Chris both have their ups and downs, certain are easier as Chris and other things are harder as Chris, Same applies to Jill. Choosing which player you want to play as really comes down to what you want to be easier and which player you prefer. Jill finds it easier with carrying things, opening things and with a few boss battles but finds it harder to use guns well and also doesn't have as much health as Chris. Chris finds it easier to aim, shoot, and has more health but has to use Old keys to open things and has less help from his partner during boss battles and also less carrying space.

Thank you guys for reading and i hope this guide helps! If you think I need to correct something or add something, Just tell me in the comments and I will fix it up! :)