Index: wp-admin/includes/media.php
===================================================================
--- wp-admin/includes/media.php	(revision 42813)
+++ wp-admin/includes/media.php	(working copy)
@@ -2996,7 +2996,16 @@
 	</div>
 	<div class="wp_attachment_details edit-form-section">
 		<p>
-			<label for="attachment_caption"><strong><?php _e( 'Caption' ); ?></strong></label><br />
+			<label for="attachment_caption"><strong>
+				<?php
+				if ( 'video' === $media_type = substr( $post->post_mime_type, 0, 5 ) ) {
+					_e( 'Media Description' );
+			 	} elseif ( 'image' === $media_type = substr( $post->post_mime_type, 0, 5 ) ) { 
+			 		_e( 'Image Caption' );
+			 	} else {
+	 				_e( 'Media Caption' ); 
+	 			} ?>
+			</strong></label><br />
 			<textarea class="widefat" name="excerpt" id="attachment_caption"><?php echo $post->post_excerpt; ?></textarea>
 		</p>
 
Index: wp-includes/css/media-views.css
===================================================================
--- wp-includes/css/media-views.css	(revision 42813)
+++ wp-includes/css/media-views.css	(working copy)
@@ -366,6 +366,7 @@
 
 .media-sidebar .setting span,
 .attachment-details .setting span {
+	max-width: 78px;
 	min-width: 30%;
 	margin-right: 4%;
 	font-size: 12px;
Index: wp-includes/media-template.php
===================================================================
--- wp-includes/media-template.php	(revision 42813)
+++ wp-includes/media-template.php	(working copy)
@@ -403,7 +403,7 @@
 				<# var maybeReadOnly = data.can.save || data.allowLocalEdits ? '' : 'readonly'; #>
 				<?php if ( post_type_supports( 'attachment', 'title' ) ) : ?>
 				<label class="setting" data-setting="title">
-					<span class="name"><?php _e( 'Title' ); ?></span>
+					<span class="name"><?php _e( 'Media Title' ); ?></span>
 					<input type="text" value="{{ data.title }}" {{ maybeReadOnly }} />
 				</label>
 				<?php endif; ?>
@@ -421,7 +421,13 @@
 				<?php endforeach; ?>
 				<# } #>
 				<label class="setting" data-setting="caption">
-					<span class="name"><?php _e( 'Caption' ); ?></span>
+					<# if ( 'video' === data.type ) { #>
+					<span class="name"><?php _e( 'Media Description' ); ?></span>
+					<# } else if ( 'image' === data.type ) { #>
+					<span class="name"><?php _e( 'Image Caption' ); ?></span>
+					<# } else { #>
+					<span class="name"><?php _e( 'Media Caption' ); ?></span>
+					<# } #>
 					<textarea {{ maybeReadOnly }}>{{ data.caption }}</textarea>
 				</label>
 				<# if ( 'image' === data.type ) { #>
@@ -431,7 +437,7 @@
 					</label>
 				<# } #>
 				<label class="setting" data-setting="description">
-					<span class="name"><?php _e( 'Description' ); ?></span>
+					<span class="name"><?php _e( 'Media Description' ); ?></span>
 					<textarea {{ maybeReadOnly }}>{{ data.description }}</textarea>
 				</label>
 				<div class="setting">
@@ -586,7 +592,7 @@
 		<# var maybeReadOnly = data.can.save || data.allowLocalEdits ? '' : 'readonly'; #>
 		<?php if ( post_type_supports( 'attachment', 'title' ) ) : ?>
 		<label class="setting" data-setting="title">
-			<span class="name"><?php _e( 'Title' ); ?></span>
+			<span class="name"><?php _e( 'Media Title' ); ?></span>
 			<input type="text" value="{{ data.title }}" {{ maybeReadOnly }} />
 		</label>
 		<?php endif; ?>
@@ -614,7 +620,7 @@
 			</label>
 		<# } #>
 		<label class="setting" data-setting="description">
-			<span class="name"><?php _e( 'Description' ); ?></span>
+			<span class="name"><?php _e( 'Media Description' ); ?></span>
 			<textarea {{ maybeReadOnly }}>{{ data.description }}</textarea>
 		</label>
 	</script>