What does "TGM" vs "TKG" mean from Sentinel 2 Images (Google Earth Engine)?

I extracted sentinel 2 images from Google Earth Engine using the Python API with something like this:

# Sentinel 2 Image Collection
s2_image_collection = ee.ImageCollection("COPERNICUS/S2_SR")

filteredCollection = s2_image_collection.filter(ee.Filter.lt("CLOUDY_PIXEL_PERCENTAGE", 5))

When I loop over the images in filteredCollection, I get the following ids:

COPERNICUS/S2_SR/20191002T162111_20191002T162929_T16TGM
COPERNICUS/S2_SR/20191002T162111_20191002T162929_T17TKG
COPERNICUS/S2_SR/20191005T163131_20191005T163713_T16TGM
COPERNICUS/S2_SR/20191005T163131_20191005T163713_T17TKG
...

I was surprised to see two images for each date. What does “T16TGM” vs “T17TKG” mean?