In addition, some of the materials used in IQ tests may be totally foreign to certain cultures, thus creating inequalities and biases. It is interesting to note that IQ scores have increased so much over the 20th century that most of today's test takers would be considered 'geniuses' by 1900 standards.
Digital subscriber line (DSL; originally digital subscriber loop) is a family of technologies that are used to transmit digital data over telephone lines.
DSL is a general term to refer the technology but we commonly used ADSL and ADSL2+ for broadband access. DSL is also there in use as a corporate VPN access method, where users need equal bandwidth for upload and download.