How does git download data? Does it store them in RAM? How does git clone / git fetch work when downloading resources?

Question

git

Downloading a large repository - over 6 gigs - with git clone. The connection breaks. Yes, ssh is more stable, without https there is a basic limit of 1 gig, but this was bypassed.
found a solution to one of the errors on the download problem - unexpected disconnect while reading sideband packet - https://stackoverflow.com/questions/66366582/githu...

export GIT_TRACE_PACKET=1
export GIT_TRACE=1
export GIT_CURL_VERBOSE=1
  
git config --global core.compression 0
git clone --depth 1 <repo_URI>
# cd to your newly created directory
git fetch --unshallow 
git pull --all

git clone --depth 1 works fine
git fetch --unshallow works great too BUT ! until I lock the screen and the ssl certificates terminate my network session.

In this connection, the question is: how does git download data? Does it store them in RAM? Doesn't create any tmp directory and redownloads the repository every time.