Suppose you receive a job application and the candidate's name starts with “S”. Right away you assume that this person is disorganised and won't do a good job just because you have a prejudice against people with the initial “S”.
Prejudices are deeply rooted, emotional judgments or beliefs about certain groups of people. These views come from one's personal feelings and experiences. Those beliefs influence how we perceive and treat people.
In a world characterised by diversity, it is important to be aware of the consequences. Not only do they affect personal relationships, but also work culture and how organisations treat their employees. To create an equitable and inclusive work environment, we need to recognise and challenge prejudices.

This definition by Allport is just one of many. It shows that prejudice is usually based on generalisations about groups rather than direct experience. With generalizations, people assume that all members of a group share the same characteristics or behaviours without questioning these assumptions or considering individual experiences. A prejudice is a negative attitude towards a person simply because they belong to a certain group. Attitudes towards social groups or their members are based on either actual or ascribed characteristics. (Sources: Allport, 1954; bpb; Hogrefe)
Stereotypes and prejudices are not the same thing, even though they are often used synonymously.
Stereotypes are generalised assumptions about a group of people, e.g. the idea that all members of a certain group share the same characteristics. These assumptions are often simplified and not always accurate, which leads to people being put into "boxes" that do not reflect their true characteristics.
Prejudices go even further: They evaluate people negatively just because they belong to a certain group. These opinions can influence our behaviour towards people. Sometimes this leads to treating people poorly simply because they are members of a specific group. This is known as discrimination.
Other words are: Bias, Aversion, Hostility. These words describe the negative feelings associated with prejudice. (Sources: bpb; EnableMe)

Stereotype: Women are emotional and less assertive.
Prejudice: Women are less suitable for management positions because it is believed that their emotionality makes them less competent in stressful situations.
Discrimination: A woman is passed over for promotion because it is assumed that she cannot make good decisions due to her emotionality.
There are many forms based on the different diversity dimensions. For example, on ethnicity, age, gender, religion or sexual orientation.
Generally speaking, prejudices can be divided into two groups: positive and negative.
However, we usually only talk about negative ones. This is because negative prejudices often lead to discrimination. In contrast, “positive” discrimination does not exist.
Examples of negative prejudices are racism, sexism, xenophobia, anti-Semitism or homophobia. There are also prejudices that relate to social differences, for example towards certain professions or social classes. (Source: bpb)
Categorisation: From an early age, we learn to quickly classify people into categories. For example: old and young. This helps us to understand the world better.
Stereotyping: When these classifications become solidified and we ascribe certain characteristics to a group, we speak of stereotyping. Prejudices therefore begin with stereotypes, simplified images that we have in our heads of groups of people. People are then no longer perceived as individuals, but rather characteristics of a certain group are projected onto them.
Evaluation: This is where we start to develop an emotional attitude and evaluate people according to their group membership. We often evaluate our own group (ingroup) more positively and other groups (outgroup) more negatively. This is how prejudices arise.
Companies have them too - including those that actively promote diversity and openness. After all, many of these prejudices are unconscious. They influence decisions significantly, especially when hiring new employees and during promotions.
This impairs equity, as candidates are treated unequally both in internal and external applications.
Women are confronted with prejudice in the world of work particularly often, mainly due to their gender. A survey by the initiative Chef:innen Sache shows that 23.7% of women experience prejudice in their day-to-day work, compared to only 9.3% of men. Prejudice impacts women in particular when they hold or aspire to management positions, as they are often perceived as less competent or assertive. (Sources: Charta der Vielfalt; Chef:innen Sache)
Direct questioning: On the one hand, people can be surveyed directly to find out their opinions and attitudes. The anonymity of surveys is particularly important in order to obtain honest feedback. Tools such as Diverlyze enable anonymous employee surveys that help to uncover attitudes and identify prejudices in a targeted manner.
Indirect measurement: On the other hand, there are indirect methods in which people's reactions are tested, e.g. based on the speed with which they react to certain statements.

Recruitment: Who is hired and who is not? Are there patterns in the candidates that are selected?
Promotions: Who is promoted? Are certain groups over- or underrepresented?
Salaries: How are salaries distributed within the company? Are employees paid fairly and on an equal basis?
Performance evaluations: How are performances assessed? Are there differences in the evaluations of certain groups?
Awareness training: e.g. recognising stereotypes, searching for counter-stereotypes.
Behavior change practices: Create positive encounters between members of different groups. When people from different groups get to know each other, the experiences gained can help to reduce prejudices.
Structural changes: Long-term measures are necessary to achieve sustainable changes. These include adjustments to selection and personnel development tools and changes to the communication strategy.