In essence, the Process explorer tool is similar to the Task Manager, as demonstrated in the following screenshot:  

The advantage of this tool is that it can show more information about the process itself, such as how it was run, including the parameters used, and even its autostart location, as can be seen in the following example:

In addition, the process explorer has tools to send it VirusTotal identification, shows a list of strings identified from its image and the threads associated with it. From a reverser's point of view, the highly used information here is the command-line usage, and autostart location. VirusTotal is an online service that scans a submitted file or URL using multiple security software, as demonstrated in the following screenshot: 

The results are not conclusive, but it gives the submitter an idea about the file's credibility of being legit software or malware.