How we can perform crud operation in Salesforce Lightning?

Lightning components don’t automatically enforce CRUD and FLS when you reference objects or retrieve the objects from an Apex controller. You will have to take care of it in your logic.

you must explicitly check for isAccessible(), isCreateable(), isDeletable(), and isUpdateable() prior to performing operations on records or objects.

Check out this :https://developer.salesforce.com/docs/atlas.en-us.lightning.meta/lightning/apex_crud_fls.htm