peform表示to do what one party is obliged to do by a contract泛指双方履行合同各项责任和义务；fulfill表示to do everything which is promised in a contract强调合同一方具体履行合同的义务

例句：

The parties hereto acknowledge that, notwithstanding any other provision of this Agreement, the General Partner, on its own behalf and/or on behalf of the Partnership, without any act, Consent or approval of any Limited Partner, may from time to time enter into, deliver and perform other written agreements with one or more Limited Partners (the "Side Letters") establishing rights under, or supplementing or altering the terms of, this Agreement and/or the Subscription Agreements with respect to one or more Limited Partners.

协议各方确认，即使本协议有任何其他规定，无需任何有限合伙人的任何行动、同意或批准，普通合伙人可代表自己和/或代表合伙企业，不时与一名或多名有限合伙人签订、交付并履行其他书面协议（“附属协议”），以确定本协议和/或认购协议下与一名或多名有限合伙人相关的权利，或者对本协议和/或认购协议下与一名或多名有限合伙人相关的条款进行补充或修改。

The Contractor shall fulfill all of its duties and obligations in carrying out its work and services hereunder。