1. A conference data management apparatus for managing meeting data, including a presentation document, corresponding to a specific meeting, the conference data management apparatus comprising: an overlay engine part that associates, in a meeting database, the presentation document and sets of overlay data, associated via a unique conference ID with the specific meeting; and a participant application part that provides a presentation user interface and presentation data through a network to a participant terminal, in response to a request from the participant terminal to participate in the specific meeting, wherein the presentation data includes the presentation document and a set of overlay data, wherein the participant application part adds user input received through the presentation user interface to the set of overlay data, wherein the user input received through the presentation user interface and added to the overlay data includes overlay data access information indicating who is authorized to access the set of overlay data, wherein the sets of overlay data associated with the presentation document, in the meeting database, include (i) a first set of overlay data in which the overlay data access information indicates public access to the first set of overlay data associated with the presentation document, and (ii) a second set of overlay data in which the overlay data access information indicates private access to the second set of overlay data associated with the presentation document, and wherein upon the apparatus receiving a request from a requestor for a specified set of overlay data, the apparatus determines based on the overlay data access information corresponding to the specified set of overlay data whether the requestor is authorized to access the specified set of overlay data, wherein the presentation user interface includes a link adding part for the participant to add an active link pointing to other content, specified by the participant through the presentation user interface at a particular moment of time, in association with a specified keyword, wherein the conference data management apparatus further comprises: a content capture database that archives specified content obtained from a content source through the network; and a content capture part that retrieves, and archives in said content capture database, said other content specified through the active link, when the participant specifies the other content at the particular moment of time through the presentation user interface, and wherein said other content archived in said content capture database is the other content obtained by the content capture part at the particular moment of time.
2. The conference data management apparatus of claim 1 , wherein the meeting database associates (i) the one or more sets of overlay data and (ii) authors of the respective sets of overlay data.