Multi-functional wireless networks are becoming promising for many modern applications, e.g., the co-design of the waveforms or the shared spectrum between sensing and localization may achieve higher spectrum efficiency. To exploit the full potential of the integrated sensing and localization network (ISLN), we try to provide the general fundamental limits of ISLN. Moreover, the power allocation strategies are formulated and solved accordingly, to show the possible tradeoffs between two different performance metrics. Numerical results are provided to validate our analysis. We can see that, (i) when the network infrastructure is limited, cooperative measurements among agents will become important. (ii) In general cases, the sensing and localization could incorporate via proper power allocation strategies. However, (iii) when the power resources are strictly limited, there will exist an obvious tradeoff between the two tasks.