SharePoint exposes a powerful search engine that can be invoked from the Advanced Search web part that is included on the default search center landing page.
However, the default configuration only allows a user to query results using the "equals" and "does not equal" operators when searching by properties.
Many users want the convenience of searching by partial matches when performing a search, since they may not remember the exact syntax of the term they are looking for. SharePoint provides two other comparison operators for this purpose-- "contains" and "does not contain". This is as close to "wildcard" searching as is available out-of-the-box.
The SharePoint search engine supports several other comparison operators, but only these two "contains" operators are available for exposure through the default configuration screens of the Advanced Search web part. Exposing other operators requires code customizations.
To enable "contains" and "does not conatin":
1) Navigate to the configuration pane for the Advanced Search web part.
2) Expand the "Properties" section to show the settings for the Properties.
3) Within this section, there is a text box that contains XML used to configure the Advanced Search web part. Click on the ellipsis to show an edit popup for the XML
4) Within the XML find the Option element named "AllowOpContains" and set the value to "True".
5) Save changes and navigate back to the screen with the Advanced Search web part. The "contains" operators should now show up in the properties drop down.