The quarterly ("stable channel") CE releases (17.03, 17.06 and so on) are supported for 4 months, and will not get new features during that period. EE quarterly releases have a 1 year support period, and also won't get new features.
During the support period, bug fixes will get back ported to those versions and released as "patch" releases (e.g. 17.03.1).
When installing, you can choose to install either the "stable" (quarterly) channel, or the "edge" (monthly) channel.
During the support period, bug fixes will get back ported to those versions and released as "patch" releases (e.g. 17.03.1).
When installing, you can choose to install either the "stable" (quarterly) channel, or the "edge" (monthly) channel.