Post-rock is a subgenre of experimental rock that emphasizes texture, atmosphere, and non-traditional song structures over conventional rock techniques. Post-rock artists often combine rock instrumentation and rock stylings with electronics and digital production as a means of enabling the exploration of textures, timbres and different styles. Vocals, when present, are often used as an instrumental layer, with many bands opting for entirely instrumental compositions. The genre began in indie and underground music scenes, but deviated.

The term post-rock was coined by music journalist Simon Reynolds and popularized in his review of Bark Psychosis' 1994 album Hex. He later expanded the concept as music "using rock instrumentation for non-rock purposes". The term has since developed to refer to bands oriented around dramatic and suspense-driven instrumental rock, making the term controversial among listeners and artists alike.

Groups such as Talk Talk and Slint are credited with producing foundational works in the style in the late 1980s and early 1990s. The release of Tortoise's 1996 album Millions Now Living Will Never Die led to post-rock becoming an established term for the genre in music criticism and journalism. In its second wave, post-rock diversified into subgenres, influencing indie rock, electronica, and certain forms of metal.

Post-rock emphasizes the use of textures, timbres, and non-rock influences, often featuring little or no vocals. Rather than relying on traditional song structures or riffs, it—as a musical aesthetic—focuses on atmosphere and mood to create a musically evocative experience. Post-rock incorporates stylings and traits from a variety of musical genres and scenes, including indie rock and its forms like slowcore and math rock, as well as krautrock, ambient music, psychedelia, progressive rock, space rock, tape music, minimalist classical, British IDM, jazz (including avant-garde jazz and cool jazz), dub, post-punk, free jazz, contemporary classical and avant-garde electronica.

First wave post-rock groups often exhibited strong influence from the krautrock of the 1970s, particularly the motorik, the characteristic krautrock rhythm, and its one- or two-chord melodicism, with these influences also being pivotal for the substyle of ambient pop, where the framework of post-rock is applied to indie pop. Post-rock acts frequently blend traditional rock instrumentation and stylistic elements with electronic and digital production, using this combination to explore a wider range of textures, timbres, and musical styles. The genre originated in the indie and underground music scenes of the 1980s and 1990s, but as it moved away from traditional rock elements, it became increasingly distinct from the conventions of indie rock of that era.

Though typically performed using standard rock instrumentation—guitars, bass, drums, and keyboards—post-rock compositions often subvert the expected uses of these instruments, for example by employing guitars as noise generators or focusing on sonic texture rather than melody. However, instruments were often used in non-traditional ways, acting as a "palette of textures" rather than for their conventional rock roles. It can be lengthy and instrumental, containing repetitive build-ups of timbres, dynamics and textures, often making use of repetition of musical motifs and subtle changes with an extremely wide range of dynamics. In some respects, this is similar to the music of Steve Reich, Philip Glass and Brian Eno, pioneers of minimalism who were acknowledged influences on bands in the first wave of post-rock.

Guitars, rather than serving melodic or riff-driven purposes, are often employed as tools for texture and atmosphere. Artists manipulate timbre through alternate tunings, effects like delay and distortion, EBows, and looping, sometimes processing guitars to the point of becoming unrecognizable. Drums and percussion in post-rock frequently defy traditional roles, drawing inspiration from krautrock's hypnotic "motorik" beats and dub's spacious, bass-heavy rhythms. It can feature, as is prominently the case in the first wave, multiple drum kits, irregular tempos, and/or minimalist patterns that prioritize mood over groove. The bass guitar often assumes a central role in shaping post-rock's atmospheric depth, diverging from standard rock's rhythmic lock with the bass drum, extending from post-punk. Influenced by dub and ambient music in addition, basslines may consist of sustained drones, pulsating loops, or sparse, resonant notes that anchor the composition's harmonic framework, differing from the walking bass trope of conventional rock.

With the increasing accessibility of samplers in the late 1980s, bands drew inspiration from contemporary electronica and experimental electronic music to restructure their compositions with sampling. Samplers, along with sequencers and MIDI setups, allowed for both ordered and chaotic elements to coexist within a single piece. The recording studio is regarded as an essential component of the creative process in post-rock. English acts such as Disco Inferno, Insides, Seefeel and Third Eye Foundation made the recording studio an active component of composition, employing hardware for live processing and sampling, and software like Cubase to sequence tracks, fragmenting and reassemble guitar sounds and vocals as abstract sonic material over drum patterns and beats.