ssh issues in powershell ,what should i do ,please explain

[sambedita]

ssh : The term 'ssh' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that
the path is correct and try again.
At line:1 char:1

• ssh -i .\ansible.pem ubuntu@13.235.45.148

•   + CategoryInfo          : ObjectNotFound: (ssh:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException