The crosshair cursor is used for pixel-perfect precision in Adobe Photoshop CC; the brush tip is for general work. To switch from crosshair cursor to brush tip, change a setting in the Cursors section of Photoshop's preferences.
Changing the Setting
Click "Edit" if you're using Windows or "Photoshop" if you're using a Mac and then hover over "Preferences" and select "Cursors." In the Painting Cursors section, select either "Normal Brush Tip" or "Full Size Brush Tip." The former option displays the cursor as an outline that is the precise shape and roughly half the size of the actual brush tip, encompassing the pixels that will be most visibly affected by the tool. The latter increases the size of the outline to match that of the actual brush tip, encompassing most of the pixels that will be affected by it.
To know precisely where you'll be painting while retaining a visual hint of which pixels will be affected by the brush, you can mark the center of the brush tip with a crosshair by enabling the "Show Crosshair in Brush Tip" check box. If you find that Photoshop's performance suffers when you're painting at large brush sizes, enabling the "Show Only Crosshair While Painting" check box may help. When you are done adjusting the settings to your liking, click "OK" to save them.