Bridges are also called store and forward devices because they look at the whole Ethernet packet before making filtering or forwarding decisions. If the segment are same,the packet is dropped (filtered).If the segments are different then the packet is forwarded to the correct segment.
A Spanning Tree Algorithm is a software standard for describing how switches and bridges can communicate to avoid n/w loops.
We cannot use bridge to connect LANs of different type and protocols because each n/w type uses different physical addressing.
Transparent Bridge-in which the host stations are unaware of their existence in the n/w.
Ethernet uses this type of bridge ,also called as adaptive bridge.