forking

What is remote and origin in git?

“remote” is just some git repository not on your computer (e.g. on github). “origin” is the repository you cloned your repository from (e.g. the one on your github). “master” is just the name of the default branch.

What is downstream and upstream in git?

As far as Git is concerned, every other repository is just a remote. Generally speaking, upstream is where you cloned from (the origin). Downstream is any project that integrates your work with other works. The terms are not restricted to Git repositories

What is a GitHub fork?

A fork is a copy of a repository. Forking a repository allows you to freely experiment with changes without affecting the original project. Most commonly, forks are used to either propose changes to someone else’s project or to use someone else’s project as a starting point for your own idea.

Syncing a fork

Sync a fork of a repository to keep it up-to-date with the upstream repository.

Before you can sync your fork with an upstream repository, you must configure a remote that points to the upstream repository in Git.

Open Git Bash.
Change the current working directory to your local project.

Fetch the branches and their respective commits from the upstream repository. Commits to master will be stored in a local branch, upstream/master.

git fetch upstream
remote: Counting objects: 75, done.
remote: Compressing objects: 100% (53/53), done.
remote: Total 62 (delta 27), reused 44 (delta 9)
Unpacking objects: 100% (62/62), done.
From https://github.com/ORIGINAL_OWNER/ORIGINAL_REPOSITORY
 * [new branch]      master     -> upstream/master

Check out your fork’s local master branch.

git checkout master
Switched to branch 'master'

Merge the changes from upstream/master into your local master branch. This brings your fork’s master branch into sync with the upstream repository, without losing your local changes.

git merge upstream/master
Updating a422352..5fdff0f
Fast-forward
 README                    |    9 -------
 README.md                 |    7 ++++++
 2 files changed, 7 insertions(+), 9 deletions(-)
 delete mode 100644 README
 create mode 100644 README.md

If your local branch didn’t have any unique commits, Git will instead perform a “fast-forward”:

git merge upstream/master
Updating 34e91da..16c56ad
Fast-forward
 README.md                 |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Configuring a remote for a fork

You must configure a remote that points to the upstream repository in Git to sync changes you make in a fork with the original repository. This also allows you to sync changes made in the original repository with the fork.

Open Git Bash.

List the current configured remote repository for your fork.

git remote -v
origin  https://github.com/YOUR_USERNAME/YOUR_FORK.git (fetch)
origin  https://github.com/YOUR_USERNAME/YOUR_FORK.git (push)

Specify a new remote upstream repository that will be synced with the fork.

git remote add upstream https://github.com/ORIGINAL_OWNER/ORIGINAL_REPOSITORY.git

Verify the new upstream repository you’ve specified for your fork.

git remote -v
origin    https://github.com/YOUR_USERNAME/YOUR_FORK.git (fetch)
origin    https://github.com/YOUR_USERNAME/YOUR_FORK.git (push)
upstream  https://github.com/ORIGINAL_OWNER/ORIGINAL_REPOSITORY.git (fetch)
upstream  https://github.com/ORIGINAL_OWNER/ORIGINAL_REPOSITORY.git (push)

Changing a remote’s URL

The git remote set-url command changes an existing remote repository URL.

The git remote set-url command takes two arguments:

An existing remote name. For example, origin or upstream are two common choices.
A new URL for the remote. For example:
- If you’re updating to use HTTPS, your URL might look like:
```
https://github.com/USERNAME/REPOSITORY.git
```
- If you’re updating to use SSH, your URL might look like:
```
git@github.com:USERNAME/REPOSITORY.git
```

Which remote URL should I use?

Refer the link: https://help.github.com/articles/which-remote-url-should-i-use/

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