So I know the rules say that if on your turn you cast a leveled spell you cannot cast another one during your turn. So like, "Cleric uses Healing Word (level 1) as bonus action, they can only cast a cantrip with their action. I got that.

But what about races that have innate spells? My example would be Eladrin with their Fey Step (1/short rest Misty Step). Since this spell is a racial ability and does NOT consume a spell slot, could an eladrin wizard Fey Step with their Bonus action and cast Fireball with their action? 

Or does it not matter and a spells a spell?

A spell is a spell.

ah

thanks!

1.  Racial spells count
2. There is no "rule say that if on your turn you cast a leveled spell you cannot cast another one during your turn".  There is a rule that says if you use a bonus action to cast a spell, then your regular action can only be used to cast a cantrip. 
3. Reactions are the most common way to cast multiple full leveled spells per round.
4. Any caster that takes 2 levels of fighter can use Action Surge to cast 2 spells on their turn once per day.  Does not include a possible two reactions as well (one before their turn, one after their turn.) 
5. It is theoretically possible to cast 4 spells and 4 cantrips in one round, although that is a very silly build in a very unusual circumstance. (17 levels Rogue (Thief), 1 level Druid, 2 levels Fighter).   Also, the spell Time Stop allows you to cast a lot of spells in one objective round.

How I and my DMs have always done it:

If the racial ability says "you can cast X spell at Y level once per long rest" (such as tieflings casting Darkness), then yes, it counts as a spell. 

If the racial ability says it is a trait (such as the eladrin's Fey Step or the firbolg's Hidden Step), then no, it does not count as a spell.

WOTC is very particular about what is and is not a spell. If the word "spell" is not in the description, it is not one. That's why clerics can Channel Divinity and cast Spiritual Weapon in the same round. 

Quote from theologyofbagels >>

How I and my DMs have always done it:

If the racial ability says "you can cast X spell at Y level once per long rest" (such as tieflings casting Darkness), then yes, it counts as a spell. 

If the racial ability says it is a trait (such as the eladrin's Fey Step or the firbolg's Hidden Step), then no, it does not count as a spell.

WOTC is very particular about what is and is not a spell. If the word "spell" is not in the description, it is not one. That's why clerics can Channel Divinity and cast Spiritual Weapon in the same round. 

 The Eladrin’s Fey Step does specify “cast”:

Fey Step

You can cast the misty step spell once using this trait. You regain the ability to do so when you finish a short or long rest.

Were you perhaps thinking of the Shadar-Kai’s Blessings of the Raven Queen?

Blessing of the Raven Queen

As a bonus action, you can magically teleport up to 30 feet to an unoccupied space you can see. Once you use this trait, you can’t do so again until you finish a long rest.

Starting at 3rd level, you also gain resistance to all damage when you teleport using this trait. The resistance lasts until the start of your next turn. During that time, you appear ghostly and translucent.

The DMG eladrin variant says "cast the Misty Step spell." Mordenkainen's, however, has it worded differently for the playable race ("As a bonus action, you can magically teleport up to 30 feet to an unoccupied space you can see. Once you use this trait, you can’t do so again until you finish a short or long rest."). Seems WOTC changed their minds about it being a spell by the time they published MToF.

That's how I read this too...via "Monsters of the Multiverse".

Fey Step is not called "Misty Step" anymore. It appears to me that it is not considered a spell but an innate ability. To me, this means an Eladriin can "Fey Step" as a bonus action and still cast a full spell with their action.

Quote from theologyofbagels >>

The DMG eladrin variant says "cast the Misty Step spell." Mordenkainen's, however, has it worded differently for the playable race ("As a bonus action, you can magically teleport up to 30 feet to an unoccupied space you can see. Once you use this trait, you can’t do so again until you finish a short or long rest."). Seems WOTC changed their minds about it being a spell by the time they published MToF.

 

 Mordenkainen's fey step also works in a different way than a basic misty step spell, since it has the extra affect based on what season you're in. So it's not even a trait that replicates misty step, it's entirely it's own thing!

(I personally think MToF's eladrins are so much better than the DMG's eladrin)

Completely agree. I started my 5th level Diviner as the DM eladrin variant but recently converted over to the MoTM (not Tomb of Foes) and it is SPECTACULAR. Three (3) Fey Steps a day as a bonus action (not a spell) and the four variants of Fey Step are simply awesome.