This author has often seen people ask the question, "How do I get strong for my sport?" The most efficient way to get strong for any sport or activity (whether football, baseball, cheerleading, wrestling, kickboxing, MMA (mixed martial arts), or something else) is to follow a routine of mostly muti-joint movements (such as squat, deadlift, overhead press, cleans, pull-ups, etc) using low reps and heavy weight. Upon receiving this answer, the person originally asking the question will often try to argue that such a routine can't be the correct answer. They think since most sports (especially combat sports) require athletes to be explosive many times over a longer period of time than just a few reps, gaining strength for their sport has to be done in a similar manner. The problem is that they don't realize the quality they are inquiring about is endurance, not strength.
Generally speaking, strength is the ability for muscles to contract powerfully, and endurance is the ability for muscles to contract repeatedly. As stated above, training primarily for strength is done by lifting heavy objects for only a few reps (usually 1-5). Endurance is trained through conditioning, which is doing 1 or more tasks for time, or for rounds of reps with little, if any, rest between rounds. Conditioning can be done with the same movements as strength training, but it also includes things like running, bearcrawls, bagwork, burpees, and so on. While the above definitions help to differentiate the two qualities, what gets people confused is that training one can, in fact, help the other.
This overlap between strength and endurance is most apparent in new trainees. Consider someone who has never done any sort of exercise or manual labor. If that person would start doing a routine of bodyweight squats, push-ups, and pull-ups, focusing on performing as many reps as possible, they will initially see an increase in their maximal strength, even though their program is actually geared toward endurance. However, the trainee will notice diminishing returns in their maximal strength gains very quickly. Even in experienced trainees, however, there is still some interplay. Increasing a person's one rep max will allow them to use heavier weight for endurance work, and increased cardiac output from conditioning will help the body recover faster from strength training, both between sets and post workout.
In other words, while strength and conditioning are two different things, they both have a place in athletic training, as well as fitness training for better health. The one who wants to be their very best will do both.