The term low hanging fruits generally stands for tasks in which maximum success can be achieved with minimal effort. Low hanging fruits in a business sense are measures which are easy to implement measures and ensure higher sales. In search engine optimization, low hanging fruits are referred to when it comes to easily implemented improvements of a website that can greatly improve the ranking of a website.
The term "Low hanging fruit" itself comes from the business sector, where it denotes tasks that generate revenue relatively quickly and with little effort. When defining business objectives for a given sector, the low-hanging fruits are the tasks that should be done first. For example, a company can start with customer satisfaction, if it is currently not as high as expected. If there are customer reports of specific problems, one can start there and improve the initial situation.
The result is not only better customer satisfaction, but also an increase in revenue. What is considered a low-hanging fruit specifically, depends on the defined objectives and the workload involved. It is important, however, to not just dedicate yourself to the easy targets exclusively, but to organize and plan your activities smartly. Moderation is the name of the game. 
Applied to SEO, low-hanging fruits are measures that bring quick results with little effort. Low cost on-page or off-page measures can achieve quick success with aiming for better positions in the search results, or KPIs (key performance indicators) such as traffic, page views and length of stay on a page can be increased. With little effort, page elements that negatively influence the bounce rate can be optimized. Adjusting the meta title or meta descriptions belongs to one of the classics in SEO.
Especially the optimization of ranking relevant titles can have a positive effect on the rankings of certain keywords within a short period of time. If the Keyword Focus on web pages is primarily aimed at longtail keywords, this can also be a low hanging fruit. The lower the competition of a keyword in the SERPs and the longer the keyword combination, the more likely it is to be successful in rankings. At the same time, e-commerce websites generally benefit more from visitors who have found their way into the shop via a longtail keyword, because these visitors have already specified their search. This increases the chance of a conversion on the website.
In the OffPage area backlinks naturally play a central role. Low hanging fruits in backlink building would be, for example, references from manufacturers to the website of an online shop. These backlinks have a great impact on the trust, but are very easy to obtain depending on the industry.