The past tense is used for things that have already happened. He was sticky. The present tense is used when something is happening now or when something happens regularly. He is sticky.

Male in hi-viz jacket: Past, present and future tenses are important because we may use the term say 'there is wear' in a component. So we'll have a look maybe it might last a bit longer so we'll ...

For example, the tense may change between the methods section and the discussion section. The abstract is usually in the past tense due to it showing what has already been studied. Example: “This ...