Differences BW Facebook Login and FBSDKLoginKit Pod and which one to use?

If you are using swift then use 'FacebookCore' and FacebookLogin'. For objective C use 'FBSDKLoginKit'. But if you see internally in podfile, they use objective C code via bridging.

You should use below pods for Login with Facebook using Swift

pod 'FacebookCore'
pod 'FacebookLogin'
pod 'FacebookShare'

Because in their official documentation's guideline for integrating Facebook Login in Swift they have mentioned those pods, so there may be some difference which they made for Swift and that's why they provide separate pods. You can assume pod 'FBSDKLoginKit' is for Objective-C because they shown Objective-C sample code on that page. Otherwise officially they haven't made any notes or declaration about these differences.

As of November 2019 the standalone swift SDK has been deprecated in favor of a single repository.

Therefore, it you should be using FBSDKCoreKit, FBSDKShareKit and FBSDKLoginKit with Cocoapods.

We plan on archiving this repo on November 1, 2019. This gives users one month to follow the instructions below for migrating to the new source code location. At this time we will also deprecate the CocoaPods FacebookCore, FacebookLogin, and FacebookShare.

The current documentation is a little bit confusing, as this section is actually referring to Swift Package Manager, not Cocoapods.

For projects that include Swift, use 'FacebookCore', 'FacebookLogin', and 'FacebookShare'

For projects that do not include Swift, use 'FBSDKCoreKit' 'FBSDKLoginKit' and 'FBSDKShareKit'