Redistribution feeds routes learned by one protocol into another at a router running both. Two facts define the behaviour: the redistributed route gets the receiving protocol’s AD, and the metric must be supplied if the target can’t invent one.

router ospf 1
 redistribute static subnets          ! subnets flag or classful-only (classic trap)
router eigrp 100
 redistribute static metric 10000 100 255 1 1500   ! EIGRP needs an explicit metric

Two-way redistribution between two IGP domains is a loop/feedback factory — filter with route-maps, keep the design one-way where possible, expect suboptimal routing.