There are two primary types of high-voltage direct current (HVDC) converters: the line-commutated converter (LCC) and the voltage-sourced converter (VSC). The LCC requires connection to an AC power source for its operation, while the VSC operates using semiconductor switches that can be actively controlled to turn on and off via gate control. LCCs consume approximately 55% of their rated active power in reactive power at full load and introduce substantial current harmonics into the connected AC system, as well as voltage harmonics on the DC side. These harmonics necessitate the use of harmonic filters on both the AC and DC sides, with capacitors serving as essential components in these filters. Conversely, VSCs inject relatively low levels of voltage and current harmonics on the DC side, often eliminating the need for harmonic filters due to their high switching frequencies. However, VSCs require large capacitors integrated within the converter valves to support their operation. The types of capacitors utilized in both LCC and VSC converters across different locations are described in this chapter, highlighting their distinct roles and requirements.