A central challenge in the design of electrical links is to compensate for frequency-dependent loss in the channel that introduces inter-symbol interference (ISI). This chapter presents the overall objectives of joint Tx/Rx equalization. The system-level operation of transmitter-side feed-forward equalizers (FFEs) is discussed. Circuit details are presented in Chapter 5. Receiver-side continuous-time linear equalizers (CTLEs) and finite-impulse-response (FIR) filters are discussed next, followed by decision-feedback equalizers (DFEs). DFEs differ from FFEs, CTLEs and FIRs in that they only remove ISI rather than attempt to invert the low-pass channel characteristic. With the growing trend toward ADC- based receivers, the implementation of DFEs and Rx FFEs is discussed in the analog domain and the digital domain. The topics in this chapter are also a relevant background for the sections in Chapter 10 that discuss TIAs for reduced bandwidth systems, where equalization is used to remove ISI from an intentionally bandwidth-limited optical receiver front-end.