Export and Import limitations:
Major drawback: The export/import does not preserve workflows instances, associations, history and tasks. Every workflow association must be recreated and there is no way to restore the running instances from original site.
If publishing feature is enabled in source site and same should be applicable for targeted site also.
How can we do the export/import of site, list and libraries along with versioning?
Use the [-IncludeVersions] option to instruct PowerShell to include version information of items in the export file.
Export-SPWeb -Identity http://sharepoint/site -Path "E:\exports\MySite.cmp" -IncludeVersions ALL
Export the sites, lists and libraries?
To export/import a specific list or library, provide the full URL to the list or library, otherwise PowerShell will import/export the site if the URL is to the main site location.
Include the [-IncludeVersions] option to instruct PowerShell to include version information of items in the export file.
Include the [-NoFileCompression] option to turn off file compression; this makes for a faster export but larger files on disk.
Include the -haltonfatalerror or -haltonwarning options to stop the import\export process in the event of an error or warning.
In SharePoint 2007, administrators could export and import sites only, using STSADM
Export and Import use in sharepoint?
Backup-SPSite is generally used when you want to replicate the entire site collection (including all subsites) to an existing web application.
Export-SPWeb is generally used when you want to replicate just a single subsite to an existing site collection.
From SP2010 onwards, you can export a site, lists and library through either central adminitrator or poweshell but we can only way to do import is through powershell.
Workflows are not included when we export/import contents of sites, libraries, or lists means Export-SPWeb does not export the running workflows.
Note: The NoFileCompression parameter lets you specify that no file compression is performed during the export process. Using this parameter can lower resource usage up to 30% during the export process. Using this parameter will result in a backup folder being created instead of a compressed file. If you use the NoFileCompression parameter in the Export-SPWeb command, you must also use it when you import the content by using the Import-SPWeb command.
includeusersecurity : Do not forget to use includeusersecurity parameter in both export and import if you wish to preserve information relative to permissions and other properties such as documents authors.