To protect against ESD: use anti-static wrist straps and mats when handling sensitive components, store components in anti-static bags, work in a controlled environment with proper grounding, use ESD-safe tools, and incorporate ESD protection devices like TVS diodes or varistors in your circuit design. CMOS and MOSFET components are particularly sensitive to ESD damage.

Analog components process continuous signals that can take any value within a range, while digital components work with discrete signals that have only specific values (typically 0 and 1). Analog components include resistors, capacitors, and operational amplifiers, while digital components include logic gates, microprocessors, and memory chips.

When selecting a capacitor, consider the capacitance value (measured in farads), voltage rating (must exceed your circuit's maximum voltage), tolerance, temperature coefficient, and type (ceramic, electrolytic, tantalum, etc.). The application determines which characteristics are most important - for example, ceramic capacitors are good for high-frequency applications, while electrolytic capacitors are suitable for power supply filtering.

Resistor color codes indicate the resistance value and tolerance. For 4-band resistors: the first two bands represent significant digits, the third band is the multiplier, and the fourth band shows tolerance. For example, red-red-brown-gold means 22 × 10¹ = 220 ohms with ±5% tolerance. 5-band and 6-band resistors provide higher precision with additional significant digits.

Through-hole components have leads that pass through holes in the PCB and are soldered on the opposite side, making them easier to handle and replace but taking more space. Surface mount (SMD/SMT) components are soldered directly onto pads on the PCB surface, allowing for smaller, more compact designs and automated assembly, but requiring more precise placement and specialized soldering techniques.