Generally, everyone having permissions to the site can access the files stored on a SharePoint site. However, if you want to share particular files or folders with some users who otherwise do not have access to the site, here is how you can do it. Also, you can also define wither the users given access to the specific files can edit or just view them. If you decide to stop sharing, you can do it anytime you want.

How To Share SharePoint files in Office 365

Share a folder or file in SharePoint

To share a folder or file in SharePoint, first select the file or folder you wish to share. And then select share. You will find a sharing dialogue box listing out the links to people inside the organization.

To change the type of link, click on the drop-down list. This will open the Details panel. Here you can modify who can access the link and if people can edit the items you are sharing.

Opting who can use this link (options can differ depending on admin settings)

Anyone receiving the link directly from you or forwarded from someone else can give access to any other user. This can also include people outside your organization. 

Chosen people give access to only the users you specify. Though other people might already enjoy access. When people forward the sharing invite, those who already have access to the item can use the link.

Turn on the edit by default. When you want people only to view your files, you must uncheck the box.

Once you followed all these steps, click Apply.

Enter the list of people you wish to share the file with and provide a message if you want. When the link is ready to send, click ‘send’.

Getting a link to the file or folder which you can copy

An alternative way to share files or folders is to get a link to the file or folder you can copy. Paste this link on a website or text message. Users with whom you share this link can forward it to others too.

Click Copy Link in SharePoint to copy the link to your clipboard.

To change the type of link, click on the drop-down list. This will open the Details panel. Here you can modify who can access the link and if people can edit the items you are sharing.

Anyone receiving the link directly from you or forwarded from someone else can give access to any other user. This can also include people outside your organization. 

Chosen people give access to only the users you specify. Though other people might already enjoy access. When people forward the sharing invite, those who already have access to the item can use the link.

Turn on the edit by default. When you want people only to view your files, you must uncheck the box.

Once you followed all these steps, click Apply.

You can paste the (Ctrl+V) anywhere you want including a text message or on a website.