storage solutions / server?

Hi

so my situation is that my macbook is almost full, and I need a longer stern storage solution. I also have a couple of other macs (for work etc) and it would be good to have a back up - home server of some sort maybe?

I would ideally want 2-4 tb of storage, but not at all sure of what the best option is.

I have high speed broadband so in theory could go for cloud, but am a little concerned over security etc.

Any suggestions would be great.

Thanks