A string of many, often equally dimensioned, resistors connected between two reference voltages is a resistor string ladder network. The resistors act as voltage dividers between the referenced voltages. Each tap of the string generates a different voltage, which can be compared with another voltage: this is the basic principle of a flash ADC (analog-to-digital converter). Often a voltage is converted to a current, enabling the possibility to use an R–2R ladder network.
Disadvantage: for an n-bit ADC, the number of resistors grows exponentially, as 2^n-1 resistors are required, while the R–2R resistor ladder only increases linearly with the number of bits, as it needs only 2n resistors.
Advantage: higher impedance values can be reached using the same number of components.