In this chapter, the connections (bridges) between chiplets are presented. Emphasis is placed on the bridges embedded in organic build-up package substrate, bridges embedded in fan-out epoxy molding compound (EMC) and redistribution-layers (RDLs), and hybrid bonding bridges. Finally, thermal-mechanical simulations of a silicon bridge connecting two chiplets with microbumps w/o underfill are presented. Also, some recommendations are provided.