Enter the email addresses or Google Groups you want to share with.
Choose what kind of access you want to grant:
Can edit—Collaborators can add and edit content as well as add comments.
Can comment (Select files only)—Collaborators can add comments, but not edit content.
Can view—People can view the file, but not edit or add comments.
If you want to control how visible your files are to other people, such as keeping them completely private or allowing anyone on the web to see them, click Advanced > Change and choose an option. The options available will depend on your admin’s settings for your organization.
Everyone you shared the document with will receive an email notification. After you've shared a file, you can get the link by selecting the file and clicking Get shareable link link.
Next to the person you want to stop sharing the file or folder with, click Remove close.
Click Save changes.
Some Important Tips
All files uploaded to Google Drive in My Drive are Private to you, unless they are uploaded in a shared folder
Only the Owner Can delete a file in Google Drive; everyone else just removes access to the file for themselves
If you Don't know if the person you are sharing a file with has a Google Account or not you can always "Share with Anyone with the link" whoever has access to click the link will be able to view the content. You can restrict this access for a certain amount of time for security purposes if you like. or in Gmail insert As Attachment from Google Drive if the file is less than 25 megabytes.