what is Lower and upper bound in optimization techniques?

what is the upper bound and lower bound in optimization techniques like PSO, GOA..etc.? In the PSO (particle swarm optimization) matlab code which is available in the matlab exchange, LB=[0 0 0] and UB=[10 10 10] is used . why it is assumed so?Please help me to know about this.

Thanks in advance.

[Walter Roberson]

Which File Exchange contribution are you looking at? The ones I look at use different bounds than that.

Answer 1

[Rajashree Annapillai]

I have attached the file which I have referred sir.