Milestone Schedule in Appendix "A". Section 1.1 Definitions.This Agreement is entered into between the Alameda Unified School District (AUSD) and. (CONTRACTOR). Seller agrees to sell to Buyer, and Buyer agrees to purchase from Seller, subject to the terms, covenants and conditions set forth herein. This form is intended for use with the California Association of REALTORS® forms RPA ("Residential Purchase. Real Property Sales and Transfers. A purchase and sale agreement is a contract between a buyer and seller for transacting a property in exchange for a specific price.