I have come across multiple different libraries for accessing Google LLMs. I am listing the ones I came across; but there may be more.

The libraries that I have seen so far:

# 1
from langchain_google_genai import ChatGoogleGenerativeAI, GoogleGenerativeAI

# 2
from langchain.chat_models import ChatVertexAI

#3 
from langchain_google_vertexai import ChatVertexAI, VertexAI, VertexAIEmbeddings

#4
import vertexai  
from vertexai.generative_models import GenerativeModel
from vertexai.language_models import TextGenerationModel

# 5
from google.generativeai import GenerativeModel

My questions:

1. Are these distinct ways or do they give access to the same set of models?
2. Which is the recommended way?

I have looked into Google Cloud Documentation, but did not come across any conclusive guide.

I have tried checking the Google Cloud Documentation, but did not come accross a conclusive guide.