A turf war is "a bitter struggle for territory, power, control, or rights". For example: a turf war erupted between street gangs; the president's resignation was the result of a turf war with the board of directors. In larger companies, turf wars can break out due to improper management further up the corporate hierarchy. It can also be described as contention for any resource between two or more parties, resulting in confrontation. The phrase may have originated in the American West, where cow herders and sheep herders fought over grazing turf.
Turf wars are fought between outlaw motorcycle clubs, street gangs, mafias, war lords, drug cartels, militant wings of political parties, or religious groups, etc. for control of a particular area or spot to sell drugs, or to collect taxation / danegeld / tribute money, or to promote one's own religious / political ideology there while stopping others trying to do the same. Examples of drug-related turf wars are the Latin American (particularly Mexican and Colombian) drug mafias/gangs trying to illegally expand and defend their "area of operations" against other rival cartels, gangs, and mafias.
Turf wars in innovation or technology could mean large companies not allowing an innovation or a new technology from a smaller company or a rival to take off by disturbing whatever is within their means, such as ecosystem, standards, devices, and usability, even though the adoption of the new technology could lead to greater sales or profitability for the company. Large companies try their best to avoid adoption of innovations of smaller start ups, which makes their own previous work irrelevant or exposes flaws or the threat of critical dependence on a monopoly supplier of that technology. These are also examples of turf wars in the sense that a smaller company or a rival has entered into a space that they had held reserved to themselves in competence and all development work sourced internally.