Square wave signals used in digital circuits can have a comparatively high frequency component included.

This capacitor is used to bypass the high frequency to ground.

• In the photograph, the capacitance of the component on the left is displayed as 104. So, the capacitance is 10 x 104 pF = 0.1 µF. The thickness is 2 mm, the height is 3 mm, the width is 4 mm.
• The capacitor to the right has a capacitance of 103 (10 x 103 pF = 0.01 µF). The height is 4 mm, the diameter of the round part is 2 mm.
• These capacitors are not polarized. That is, they have no polarity.

These capacitors have the shape of a disk. Their capacitance is comparatively small.

• The capacitor on the left is a 100pF capacitor with a diameter of about 3 mm.
• The capacitor on the right side is printed with 103, so 10 x 103pF becomes 0.01 µF. The diameter of the disk is about 6 mm.
• Ceramic capacitors have no polarity.
• Ceramic capacitors should not be used for analog circuits, because they can distort the signal.