Most, if not all, consumer-grade home electronics such as stereo amplifiers, turntables (remember those), tape decks, tuners, equilizers, televisions, computers, VHS players, DVD players, etc. all use unbalanced inputs/outputs -- the familiar RCA phono connectors -- so is why you're more familiar with those.
Professional audio/PA equipment such as mixers usually use balanced inputs (the XLR connectors) for microphones, but also usually have unbalanced inputs as an option on each channel. Unbalanced inputs are usually realized as 1/4-inch phone jacks and plugs, e.g., the inputs to a guitar amplifier. I don't know of any balanced phone jack/plug configuration whether 2.5mm, 3.5mm or 1/4-inch.
Dean