Each OSGi container provides a different default target start level; for Equinox, the default is 6, whilst for Felix it is 1.
每个OSGi容器都提供了不同的默认目标级别：Equinox默认值是6；而Felix是1。
These are based on the concept of UNIX run levels; the system starts at level one, and then monotonically increments until it hits the target start level.
这一概念是基于UNIX运行级别的概念：系统以级别1启动，然后单调递增，直到达到目标启动级别。
Start levels can therefore be used to create an ordering between bundles, by putting key bundle services (like logging) into a lower start level than those that require it.
启动级别可被用来创建bundle间的启动顺序，让关键bundle服务（比如logging）的启动级别比那些需要用它的bundle更低。
The products will launch plug-ins with Start Level 0.
产品将先启动Start Level0 的插件。
The products will launch plug-ins with Start Level 0.
产品将先启动Start Level0 的插件。
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