Hi Ravi,

Pending Deployments

You can initiate multiple deployments. Only one deployment can run at a time. The other deployments will remain in the queue waiting to be executed after the current deployment finishes. Queued deployments are listed under Pending Deployments in the order they will be executed.

Deployment Validations

A deployment validation is a deployment that is used only to check the results of deploying components and is rolled back. A validation doesn't save any deployed components or change the organization in any way. You can determine whether a deployment is a validation only (Validate) or an actual deployment (Deploy) by inspecting the information for pending deployments or the Status column of deployments in the Failed and Succeeded sections.

If a validation completed successfully in the last four days, and all tests passed with sufficient code coverage, you can perform a quick deployment by deploying this validation to production without running tests. See Quick Deployments.

Canceling a Deployment

You can cancel a deployment while it’s in progress or in the queue by clicking Cancel next to the deployment. The deployment then has the status Cancel Requested until the deployment is completely canceled. A canceled deployment is listed in the Failed section.

Completed Deployments

Deployments that have finished are listed either in the Failed or Succeeded sections depending on their status.

Deployments that have finished but failed, and deployments that were canceled are listed in the Failed section. No changes were committed to the organization for these deployments because files were missing, components had errors, tests failed, or the deployment was canceled.

Deployments that have completed successfully or have partially succeeded are listed in the Succeeded section. Only deployments to a non-production organization can partially succeed. These are deployments that have the rollbackOnError field set to false in the deployment options and have errors in a subset of components. In a partially succeeded deployment, the failed components aren’t committed and the remaining components are committed to the organization.

To get more details about a deployment, click View Details next to a deployment. Use the information on the Deployment Details page to view the errors and troubleshoot problems for a failed or partially succeeded deployment. The Deployment Details page includes the error messages that occurred during the deployment, errors for Apex tests with stack trace information, code coverage warnings, and information about slow tests. For a successful deployment, the Deployment Details page shows information about the deployment including how many components were deployed and how many Apex tests were run.

Please let me know if the link below along with the information helps you

http://www.salesforce.com/us/developer/docs/dev_lifecycle/Content/migrate_monitor.htm

Best Regards
Naga kiran