What is the Gemini Files API and when do you need it?

from google import genai
from pathlib import Path

client = genai.Client()

# Upload a file
uploaded = client.files.upload(
    file=Path("large-document.pdf"),
    config={"display_name": "Q3 Report"}
)
print(f"File URI: {uploaded.uri}")
print(f"MIME type: {uploaded.mime_type}")
print(f"State: {uploaded.state}")  # PROCESSING | ACTIVE | FAILED

# Wait for processing (videos may take time)
import time
while uploaded.state == "PROCESSING":
    time.sleep(2)
    uploaded = client.files.get(name=uploaded.name)

# Use in multiple requests without re-uploading:
for question in ["Summarise section 2", "List all action items", "Find risks"]:
    response = client.models.generate_content(
        model="gemini-3.5-flash",
        contents=[
            question,
            types.Part(file_data=types.FileData(file_uri=uploaded.uri))
        ]
    )
    print(response.text)

# List and delete files:
for f in client.files.list():
    print(f.name, f.display_name)
client.files.delete(name=uploaded.name)