Teesside mainly associated with the local petrochemical, chemical and steel processing industries. The port is an important piece of logistical infrastructure for the NEPIC cluster of process companies. Teesside continues to be used locally to refer the entire urban area and the name can still be seen in the following uses: It has also been adopted for various other purposes as a synonym for the former county of Cleveland. It is common to see Teesside spelled incorrectly as "Teeside", with a single 's'. Teesside Teesside () is the conurbation in the north east of England around the urban centre of Middlesbrough
Teesside Cleveland, Yorkshire and Durham are frequently used, such as the continued existence of Cleveland Police and Cleveland Fire and Rescue Service, and of the Cleveland postal county. The Teesside Built-up Area (BUA), previously the Teesside Urban Area, identified by the ONS for statistical purposes had a population of around 376,633 according to the 2011 census which is up 3% on the 2001 figure of 365,323, and had the following subdivisions: Eaglescliffe and Yarm are counted as a separate Yarm urban area, separated by a narrow gap, which had a population of 19,184 according to the 2011 census up 5% from