Preservation:

(1) The basic responsibility to provide adequate facilities for the protection, care and maintenance of archives, records, and manuscripts.

(2) Specific measures, individual and collective, undertaken for the repair, maintenance, restoration, or protection of documents.

                                        -- SAA Glossary, 1972 --

Preservation:

"The totality of processes and operations involved in the stabilization and protection of documents against damage or deterioration and in the treatment of damaged or deteriorated documents. Preservation may also include the transfer of information to another medium, such as microfilm."

                                                -- SAA Glossary, 1996 --

Conservation:

Conservation encompasses three explicit functions: examination, preservation, and restoration.

                                                -- National Conservation Advisory Council, 1976 --

Conventional Wisdom:

Preservation places emphasis on prevention and management processes (though not exclusively).

Conservation places emphasis on treatment (though not exclusively)