Co-polymer

Note: Copolymers that are obtained by copolymerization of two monomer species
are sometimes termed bipolymers, those obtained from three monomers terpolymers,
those obtained from four monomers quaterpolymers, etc.

Alternating copolymers: A copolymer consisting of macromolecules comprising
two species of monomeric units in alternating sequence.

Note: An alternating copolymer may be considered as a homopolymer derived from
an implicit or hypothetical monomer.

Block copolymers: A portion of a macromolecule, comprising many constitutional
units, that has at least one feature which is not present in the adjacent portions.

When two or more different monomers unite together to polymerize, their result is called a copolymer and its process is called copolymerization. Monomers typically have a double-bond or a triple-bond that undergoes a cross-linking reaction with another molecule to form a new single bond between monomers. Double bonds that participate in polymerization reactions include C=C double bonds, C=N double bonds, and C=O double bonds. Triple bonds that participate in polymerization typically can include carbon-carbon triple bonds (ethylene groups) and carbon-nitrogen triple bonds(nitrile groups).

Commercially relevant copolymers include acrylonitrile butadiene styrene (ABS), styrene/butadiene co-polymer (SBR), nitrile rubber, styrene-acrylonitrile, styrene-isoprene-styrene (SIS) and ethylene-vinyl acetate.

Since a copolymer consists of at least two types of constituent units (also structural units), copolymers can be classified based on how these units are arranged along the chain. These include:

Copolymers may also be described in terms of the existence of or arrangement of branches in the polymer structure. Linear copolymers consist of a single main chain whereas branched copolymers consist of a single main chain with one or more polymeric side chains.

...
Wikipedia