Neutron reflectometry (NR) is a versatile technique that has been used in a wide range of research activities in physics, chemistry, biology, and materials science. Specular NR determines the profile of the atomic density and magnetization along the surface normal with nanometer resolution. Therefore, NR experiments address scientific phenomena occurring at the nanoscale, that is, at the surface or interfaces of single thin films or multilayered structures with thicknesses usually in the range from 1 to 100 nm. This provides a brief introduction into the theoretical and practical aspects of specular NR for the nonexpert. A list of references of typical NR experiments covering a wide range of scientific problems is given to help researchers in how NR could be applied to solve scientific problems in their own area of expertise. A few NR experiments are discussed in more detail to showcase the unique capabilities of NR.Keywords:neutron reflectometry;thin films;nanostructure;multilayers;interface/surface effects;magnetic structure;exchange bias;polymer films;surfactants;swelling;hydrogen absorption