Test beds are the environments in which the standard tasks 
may be implemented. The purpose of a test bed is to provide 
metrics for evaluation (objective comparison) and to lend 
the experimenter a fine-grained control in testing agents

http://ai.eecs.umich.edu/cogarch0/common/theory/testbed.html

means the collectivity of test data and test gaidelines

An environment that is created for testing purposes. A test 
bed may refer to software only or to both hardware and 
software

In my view Test bed includes Test Environment(both hardware 
and software platforms) along with infrastucture and data 
guidelines e.t.c..

Test bed is the environment required to execute the tests
which includes both hardware and software components.

It is an environment  created for testing purposes. A test 
bed may refer to software only or to both hardware and 
software

As I Know Test Bed is the environment created for a specific
testing in a given hardware and software configuration.

test beds are software and hardware platforms required to 
execute the test cases