What does 'bump' mean?

[Pink Jumper]

I have been a member of this forum for a couple of months now and people say 'bump' all the time but I am still not sure what it means? :red

 

[Sodapops]

It's what people do to keep a particular post at the top of the page - in other words 'bumping it up'

 

[Pink Jumper]

Really! Aw thanks, well I didn't know that! xx

 

[BossHogg]

Every day's a school day.