In communications and electronics, especially in telecommunications, interference is anything which modifies, or disrupts a signal as it travels along a channel between a source and a receiver. The term typically refers to the addition of unwanted signals to a useful signal. Common examples are:

• Electromagnetic interference (EMI)
• Co-channel interference (CCI), also known as crosstalk
• Adjacent-channel interference (ACI)
• Intersymbol interference (ISI)
• Inter-carrier interference (ICI), caused by doppler shift in OFDM modulation (multitone modulation).
• Common-mode interference (CMI)
• Conducted interference