Polytechnic Institute of Paris different from Paris-Saclay University
History
After World War II, the rapid growth of nuclear physics and chemistry meant that research needed more and more powerful accelerators, which required large areas. The University of Paris, the École Normale Supérieure and the Collège de France looked for space in the south of Paris near Orsay. The Orsay branch of the University of Paris eventually became an independent university, called Paris Sud University. In 1976, the École polytechnique joined the region, by moving from central Paris to Palaiseau. Other institutes joined the region in the following decades, most notably ENS Cachan, Télécom Paris, and ENSTA, as part of the Paris-Saclay project, a national effort to regroup research and business activities.
In 2015, these institutes were grouped together as a university community (ComUE) called Paris-Saclay University. The goal was to be recognized as an entity of sufficient size and quality, and to become a top-ranking, research-focused French university. Each member institution would remain independent but share a significant portion of existing and newly invested resources. This follows a model similar to the one adopted by University of Oxford and Cambridge, where each constituent college keeps its independence while being grouped under a 'university'.
Confronted with disagreements between its members (engineering schools versus universities, French Ministry of Defense versus Ministry of Higher Education), the University of Paris-Sud proposed to transform itself into Paris-Saclay University in 2017, with the engineering schools being only associated to the future institution. On October 25, 2017, the French president Emmanuel Macron announced the creation of a second university pole in Paris-Saclay, which would split away from Paris-Saclay University and regroup the engineering schools. This new pole was initially called "NewUni", and became the Polytechnic Institute of Paris in February 2019. 
HEC Paris also joined the new university pole without becoming a member. Other higher education or research institutions may join in the future. Paris-Saclay University and the Polytechnic Institute of Paris co-operate in several master's degrees and PhD programsOn September 15, 2020, the Institute co-founded with HEC Paris the artificial intelligence research center Hi! PARIS.
not same as not identical to distinct from separate from unlike