Your forks are probably the single most complex and expensive component on your bike.
To get the best performance and lifespan out of them, you need to do some routine basic servicing.
A lowers service is a simple standard maintenance task that most home mechanics can perform if done slowly and with care. If not done within the suggested service interval, then your fork can become irrevocably damaged and expensive to repair or replace.
In this video we perform this service on a Rock Shox SID fork, replacing the dust seals and re-assembling with lubes and oils.