A new generation of survey telescopes with large etendues (the product of field of view and
collecting area), are detecting and resporting variable astrophysical events in the form of large
astronomical alert streams. In particular, the Zwicky Transient Facility has been producing
approximately 300 k alerts per night since 2018 and the Vera C. Rubin Observatory will produce
about 10 M alerts per night since 2024. In order to make sense of these large alert streams a
new type of system is needed: the astronomical alert brokers. Several brokers have been
processing the alert stream from ZTF, and seven brokers have been selected as Community
Brokers for the Vera C. Rubin Observatory and its Legacy Survey of Space and Time (LSST):
ALeRCE, ANTARES, AMPEL, Babamul, Fink, Lasair and Pitt-Google. These brokers will
become intermediaries between survey telescopes and follow-up resources and will offer
different services for the general community to provide access to the alert stream and enable
the best science from these data. In this tutorial we will present the tools and services provided
by the ALeRCE broker.