With the Layer Opacity and Fill settings in Adobe Photoshop CC, you can make anything slightly or completely transparent. Using a file format that supports transparency ensures that your background doesn't get filled in after you've made it transparent.
Using Layer Transparency
Select the layer that you want to make transparent and then click the Opacity menu in the Layers panel. Drag the slider to the left or enter a number in the Opacity menu.
The lower the Opacity, the more transparent the layer becomes. Reducing the Opacity to zero makes the layer completely transparent so it's no longer visible in the canvas.
Just below the Opacity menu in the Layers panel, you'll find the Fill menu. With most layer types, reducing the Fill percentage has exactly the same effect as reducing the Opacity. Where the difference between Opacity and Fill becomes apparent is on layers with lines and fill, like vectors and shapes, as well as layers with Filter effects like a drop shadow. Reducing Fill doesn't affect lines or effects.
Making Transparent Backgrounds
Click the Lock icon on the Background layer in the Layers panel to make it editable.
Click the Opacity menu and drag the slider all the way to the left, or type 0 in the Opacity menu, to reduce the opacity to zero. Wherever you see a gray checkerboard on the canvas, that area will be transparent when you save the image.
Save the image in any format that supports background transparency, including PSD, PNG or GIF. If you use the Save For Web option, make sure that the Transparency check box is checked before saving the image. Note that JPG images don't support transparency and will fill in the transparent areas with white.