What is space debris ? How this debris is managed ?

Explanation

(i)In additional to artifical satellites, some other objects also revoleve around the earth . They incluce non-functional parts of satellites , detached parts of launcher, pieces due to collision of satellites.
(ii) Thus debris can be harmful to the artifical satellites. They can collide with the satellites or space carfts and damage them . Sonn it will be very difficult to launch new space carft .
(iii) How is it manged .