Perfect absorbers (PAs) are devices that can efficiently absorb electromagnetic waves. Great attention has been attracted since metamaterial PAs (MPAs) were first proposed in 2008. In recent years, with the development of nanophotonics and the improvement of nanomanufacturing technology, considerable progresses have been achieved in designing MPAs using new materials and new structures. In this review, we summarized first the latest developments of PAs from five directions: dual-band, multi-band, wideband, narrow-band, and tunable light absorption. The shortcomings of the previous PAs and the latest improvements were introduced as well. Then, the application of perfect absorption in solar cells, sensors, switches, and structural colors was discussed. Finally, we presented the main challenges and prospects in these fields. Novel PAs for applications in a wide field of opto-electronic devices will continuously progress with breakthrough advances in absorbers related technology and science.