中文：

QDII是合格境内机构投资者的缩写，是在一国境内设立，经中国有关部门批准从事境外证券市场的股票、债券等有价证券业务的证券投资基金。简单来说，QDII基金就是帮助国内投资者投资境外市场的基金。

QDII的出现主要是为了缓解国内资本市场的资金流动性过剩问题，同时也为国内投资者提供了更加广阔的投资空间和机会。通过投资QDII基金，投资者可以间接投资境外市场，获取全球市场的投资收益。

与传统的证券投资基金相比，QDII基金的投资范围更广泛，投资策略也更加灵活。它不仅可以投资于股票、债券等传统证券品种，还可以投资于基金、房地产等其他资产类型。此外，QDII基金的投资目标也更加多样化，有的追求高收益，有的注重资产配置的平衡和稳健。

总的来说，QDII是一种帮助投资者拓宽投资渠道、提高投资收益的金融工具。但是，投资者在选择QDII基金时也需要注意风险和合规问题，了解基金的投资策略、资产配置和风险收益特征等信息，并根据自身风险承受能力和投资目标进行合理选择。

英文：

QDII is the abbreviation of Qualified Domestic Institutional Investors, which refers to domestic institutions that are established in China and approved by relevant Chinese authorities to invest in overseas securities markets such as stocks and bonds. In other words, QDII funds are funds that help domestic investors invest in overseas markets.

The emergence of QDII is mainly to alleviate the problem of excess liquidity in the domestic capital market, and also to provide domestic investors with a broader investment space and opportunities. By investing in QDII funds, investors can indirectly invest in overseas markets and obtain investment returns from global markets.

Compared with traditional securities investment funds, QDII funds have a broader investment scope and more flexible investment strategies. They can not only invest in traditional securities such as stocks and bonds, but also invest in other asset types such as funds and real estate. In addition, the investment objectives of QDII funds are also more diverse, with some pursuing high yields, while others focus on balanced and stable asset allocation.

Overall, QDII is a financial tool that helps investors expand investment channels and increase investment returns. However, investors need to pay attention to risks and compliance issues when selecting QDII funds, understand the fund's investment strategy, asset allocation, and risk and return characteristics, and make reasonable choices based on their own risk tolerance and investment objectives.