  The rate of star formation varies between galaxy types and evolves with
redshift. Most stars in the universe have formed in episodes of an
exceptionally high star-forming activity, commonly called a starburst. We here
summarize basic definitions and general properties of starbursts, together with
their observational signatures.We overviewthe main types of starburst galaxies
both in the local universe and at high redshift, where they were much more
common. We specify similarities and differences between the local and distant
samples and specify the possible evolutionary links. We describe the role of
starburst galaxies in the era of cosmic reionization, relying on the most
recent observational results.
